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UC-NRLF 


LIBRARY 

OF  THE 

UNIVERSITY  OF  CALIFORNIA. 


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GIFT    OF 


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U.  S.  DEPARTMENT  OF  AGRICULTURE. 

BUREAU  OF  PLANT  INDUSTRY     BULLETIN  No.  64. 


METHOD  OF  DESTROYING  OR  PREVENTING 
THE  GROWTH  OF  ALG.E  AND  CERTAIN 
PATHOGENIC  BACTERIA  IN 
WATER  SUPPLIES. 


GEORGE    T.^MOORE. 

PIIY>I(  >i.<  rcisr  AND  ALGOLOGIST  IN  CHARGE  OF  LABORATORY 
OF  PLANT  PHYSIOLOGY, 


KARL   F.    KELLERMAN. 

ASSISTANT  IN  PHYSIOLOGY. 


VEGETABLE    PATHOLOGICAL    ANJD    PHYSIOLOGICAL 
INVESTIGATIONS. 


i)  MAY   7,  1904. 


WASHINGTON: 

<;ov  i:  KN  .M  i:  NT    IMJTNTING    OFFICE, 
1  1*04. 


BULLETINS  OF  THE  BUREAU  OF  PLANT  INDUSTRY. 

The  Bureau  of  Plant  Industry,  which  was  organized  July  1,  1901,  includes  Vege- 
table Pathological  and  Physiological  Investigations,  Botanical  Investigations  and 
Experiments,  Grass  and  Forage  Plant  Investigations,  Pomological  Investigations, 
and  Experimental  Gardens  and  Grounds,  all  of  which  were  formerly  separate  Divi- 
sions, and  also  Seed  and  Plant  Introduction  and  Distribution,  the  Arlington  Exper- 
imental Farm,  Tea-Culture  Investigations,  and  Domestic  Sugar  Investigations. 

Beginning  with  the  date  of  organization  of  the  Bureau,  the  several  series  of  bulle- 
tins of  the  various  Divisions  were  discontinued,  and  all  are  now  published  as  one 
series  of  the  Bureau.  A  list  of  the  bulletins  issued  in  the  present  series  follows. 

Attention  is  directed  to  the  fact  that  "the  serial,  scientific,  and  technical  publica- 
tions of  the  United  States  Department  of  Agriculture  are  not  for  general  distribution. 
All  copies  not  required  for  official  use  are  by  law  turned  over  to  the  Superintendent 
of  Documents,  who  is  .empowered  to  sell  them  at  cost."  All  applications  for  such 
publications  should,  therefore,  be  made  to  the  Superintendent  of  Documents,  Gov- 
ernment Printing  Office,  Washington,  D.  C. 
No.  1.  The  Eelation  of  Lime  and  Magnesia  to  Plant  Growth.  1901.  Price,  10  cents. 

2.  Spermatogenesis  and  Fecundation  of  Zamia.     1901.     Price,  20  cents. 

3.  Macaroni  Wheats.     1901.     Price,  20  cents. 

4.  Kange  Improvement  in  Arizona.     1902.     Price,  10  cents. 

5.  Seeds  and  Plants  Imported.     Inventory  No.  9.     1902.     Price,  10  cents. 

6.  A  List  of  American  Varieties  of  Peppers.     1902.     Price,  10  cents. 

7.  The  Algerian  Durum  Wheats.     1902.     Price,  15  cents. 

8.  A  Collection  of  Fungi  Prepared  for  Distribution.     1902.     Price,  10  cents. 

9.  The  North  American  Spejgies  of  Spartina.     1902.     Price,  10  cents. 

10.  Records  of  Seed  Distribution  and  Cooperative  Experiments  with  Grasses  and 

Forage  Plants.     1902.     Price,  10  cents. 

11.  Johnson  Grass.     1902.     Price,  10  cents. 

12.  Stock  Eanges  of  Northwestern  California:  Notes  on  the  Grasses  and  Forage 

Plants  and  Range  Conditions.     1902.     Price,  15  cents. 

13.  Experiments  in  Range  Improvement  in  Central  Texas.     1902.     Price,  10 

cents. 

14.  The  Decay  of  Timber  and  Methods  of  Preventing  It.     1902.    Price,  55  cents. 

15.  Forage  Conditions  on  the  Northern  Border  of  the  Great  Basin.     1902.     Price, 

15  cents. 

16.  A  Preliminary  Study  of  the  Germination  of  the  Spores  of  Agaricus  Campes- 

tris  and  other  Basidiomycetous  Fungi.     1902.     Price,  10  cents. 

17.  Some  Diseases  of  the  Cowpea.     1902.     Price,  10  cents. 

18.  Observations  on  the  Mosaic  Disease  of  Tobacco.     1902.     Price,  15  cents. 

19.  Kentucky  Bluegrass  Seed:  Harvesting,  Curing,  and  Cleaning.     1902.    Price, 

10  cents. 

20.  Manufacture  of  Semolina  and  Macaroni.     1902.     Price,  15  cents. 

21.  List  of  American  Varieties  of  Vegetables.     1903.     Price,  35  cents. 

22.  Injurious  Effects  of  Premature  Pollination.     1902.     Price,  10  cents. 

23.  Berseem:  The  Great  Forage  and  Soiling  Crop  of  the  Nile  Valley.     1902. 

Price,  15  cents. 

24.  Unferrnented  Grape  Must.     1902.     Price,  10  cents. 

25.  Miscellaneous  Papers:  I.  The  Seeds  of  Rescue  Grass  and  Chess.     II.  Saragolla 

Wheat.  III.  Plant  Introduction  Notes  from  South  Africa.  IV.  Congres- 
sional Seed  and  Plant  Distribution  Circulars.  1902-1903.  1903.  Price, 
15  cents. 

26.  Spanish  Almonds  and  Their  Introduction  into  America.     1902.     Price,  15 

cents. 

[Continued  on  p.  3  of  cover.] 


U.  S.  DEPARTMENT   OF  AGRICULTURE, 

BUREAU  OF  PLANT  INDUSTRY— BULLETIN  No.  64. 

B.  T.  GALLOWAY,  Chief  of  Bureau. 


A  METHOD  OF  DESTROYING  OR  PREVENTING 

THE  GROWTH  OF  ALG.E  AND  CERTAIN 

PATHOGENIC  BACTERIA  IN 

WATER  SUPPLIES. 


BY 


GEORGE    T.    MOORE. 

PHYSIOLOGIST  AND  ALGOLOGIST  IN  CHARGE  OF  LABORATORY 
OF  PLANT  PHYSIOLOGY, 


AND 


KARL    F.    KELLERMAN, 
ASSISTANT  IN  PHYSIOLOGY. 


VEGETABLE    PATHOLOGICAL.    AND    PHYSIOLOGICAL 
INVESTIGATIONS. 


ISSUED  MAY  7,  1904. 


WASHINGTON: 

GOVERNMENT     PRINTING     OFFICE 
1904. 


BUEEAU  OF  PLANT  INDUSTRY. 


B.  T.  GALLOWAY,  Chief. 
J.  E.  ROCKWELL,  Editor. 


VEGETABLE  PATHOLOGICAL  AND  PHYSIOLOGICAL  INVESTIGATIONS. 

SCIENTIFIC   STAFF. 

ALBERT  F.  WOODS,  Pathologist  and  Physiologist. 


ERWIN  F.  SMITH,  Pathologist  in  Charge  of  Laboratory  of  Plant  Pathology. 

GEORGE  T.  MOORE,  Physiologist  in  Charge  of  Laboratory  of  Plant  Physiology. 

HERBERT  J  WEBBER,  Physiologist  in  Charge  of  Laboratory  of  Plant  Breeding. 

WALTER  T.  SWINGLE,  Physiologist  in  Charge  of  Laboratory  of  Plant  Life  History. 

NEWTON  B.  PIERCE,  Pathologist  in  Charge  of  Pacific  Coast  Laboratory. 

M.  B.  WAITE,  Pathologist  in  Charge  of  Investigations  of  Diseases  of  Orchard  Fruits. 

MARK  A.  CARLETON,  Cerealist  in  Charge  of  Cereal  Investigations. 

HERMANN  VON  SCHRENK,^  in  Charge  of  Mississippi  Valley  Laboratory. 

P.  H.  ROLFS,  Pathologist  in  Charge  of  Subtropical  Laboratory. 

C.  O.  TOWNSEND,  Pathologist  in  Charge  of  Sugar  Beet  Investigations. 

P.  H.  DORSETT,  Pathologist. 

RODNEY  H.  TRUE,&  Physiologist. 

T.  H.  KEARNEY,  Physiologist,  Plant  Breeding. 

CORNELIUS  L.  SHEAR,  Pathologist. 

WILLIAM  A.  ORTON,  Pathologist. 

W.  M.  SCOTT,  Pathologist. 

JOSEPH  S.  CHAMBERLAIN,  Physiological  Chemist,  Cereal  Ivestigations.  * 

R  E.  B  MCKENNEY,  Physiologist. 

FLORA  W.  PATTERSON,  Mycologist. 

CHARLES  P  HARTLEY,  Assistant  in  Physiology,  Plant  Breeding. 

KARL  F.  KELLERMAN,  Assistant  in  Physiology. 

DEANE  B.  SWINGLE,  Assistant  in  Pathology. 

A.  W.  EDSON,  Scientific  Assistant,  Plant  Breeding. 

JESSE  B.  NORTON,  Assistant  in  Physiology,  Plant  Breeding. 

JAMES  B.  RORER,  Assistant  in  Pathology. 

LLOYD  S.  TENNY,  Assistant  in  Pathology. 

GEORGE  G  HEDGCOCK,  Assistant  in  Pathology. 

PERLEY  SPAULDING,  Scientific  Assistant. 

P.  J.  O'GARA,  Scientific  Assistant. 

A.  D-  SHAMEL,  Scientific  Assistant,  Plant  Breeding. 

T.  RALPH  ROBINSON,  Scientific  Assistant,  Plant  Physiology. 

FLORENCE  HEDGES,  Scientific  Assistant,  Bacteriology. 

CHARLES  J.  BRAND,  Scientific  Assistant  in  Physiology,  Plant  Life  History. 

a  Detailed  to  the  Bureau  of  Forestry. 

b  Detailed  to  Botanical  Investigations  and  Experiments. 


LETTER  OF  TRANSMITTAL 


U.  S.  DEPARTMENT  OF  AGRICULTURE, 
BUREAU  OF  PLANT  INDUSTRY, 

OFFICE  OF  THE  CHIEF, 
Washington,  D.  <?.,  April  30,  1904. 

SIR:  I  have  the  honor  to  transmit  herewith  a  paper  entitled  "A 
Method  of  Destroying  or  Preventing  the  Growth  of  Algae  and  Certain 
Pathogenic  Bacteria  in  Water  Supplies,"  and  to  recommend  that  it  be 
published  as  Bulletin  No.  64  of  the  series  of  this  Bureau. 

The  paper  was  prepared  by  George  T.  Moore,  in  charge  of  Labora- 
tory of  Plant  Physiology,  and  Karl  F.  Kellerman,  Assistant  in  Physi- 
ology, in  the  Office  of  Vegetable  Pathological  and  Physiological 
Investigations,  and  was  submitted  by  the  Pathologist  and  Physiologist 
with  a  view  to  publication.  The  subject  discussed  in  this  bulletin 
will  be  of  interest  and  value  to  all  who  have  to  deal  with  the  problem 
of  preventing  algal  and  other  contamination  of  water  supplies. 
Respectfully, 

B.  T.  GALLOWAY, 

Chief  of  Bureau. 
Hon.  JAMES  WILSON, 

Secretary  of  Agriculture. 

3 


218532 


PREFACE. 


The  necessity  of  finding  some  cheap  and  practical  method  of  prevent- 
ing or  removing  algal  contamination  of  cress  beds  first  led  this  Office 
to  undertake  the  investigations  described  in  this  bulletin.  The  success 
of  the  first  experiments  in  1901  was  so  marked  that  it  seemed  wise  to 
extend  the  work,  and  authority  was,  therefore,  granted  by  Congress 
"to  study  and  find  methods  for  preventing  the  algal  and  other  con- 
taminations of  water  supplies." 

The  progress  of  the  investigation  has  been  noted  from  time  to  time 
in  the  annual  reports  of  the  Bureau.  Though  the  work  is  not  yet  com- 
pleted, we  have  been  urged  to  publish  the  results  already  obtained  for 
the  consideration  of  boards  of  health  and  officers  in  charge  of  public 
water  supplies. 

Doctor  Moore  and  Mr.  Kellerman  have  shown  that  it  is  entirely 
practicable  to  cheaply  and  quickly  destroy  objectionable  alga?  in  small 
lakes,  ponds,  storage  reservoirs,  and  other  similar  bodies  of  water  by 
the  use  of  extremely  dilute  solutions  of  copper  sulphate  or  of  metallic 
copper.  The  fact  that  an  extremely  dilute  solution  (one  to  one 
hundred  thousand)  will  also  destroy  the  most  virulent  typhoid  and 
cholera  bacteria  at  ordinary  temperatures  in  three  hours  is  of  great 
importance  and  significance.  Solutions  of  copper  as  dilute  as  this 
are  not  considered  injurious  to  man  or  other  animals.  The  value  of 
copper,  especially  colloidal,  in  preventing  or  treating  typhoid  and 
other  related  diseases  should  be  carefully  investigated  by  competent 
pathologists. 

We  desire  it  distinctly  understood  that,  so  far  as  bacterial  contami- 
nation of  water  is  concerned,  the  methods  here  proposed  are  not  to 
take  the  place  of,  but  are  simply  to  supplement  the  standard  methods 
of  filtration;  neither  can  too  much  stress  be  laid  upon  the  importance 
of  the  consumer  boiling  water  to  be  used  for  drinking  purposes  when 
taken  from  a  contaminated  source. 

Upon  application  to  the  Department  by  proper  authorities,  infor- 
mation and  assistance  will  be  furnished  in  determining  the  organisms 
causing  the  trouble  in  cases  of  algal  pollution,  and  the  proper  treat- 
ment will  be  recommended.  Jt  is  earnestly  hoped  that  no  test  of  the 
method  described  here  will  be  made  without  first  consulting  the 
Department. 

5 


6  PREFACE. 

As  stated  in  the  text  of  the  bulletin — 

The  treatment  of  water  supplies  for  the  destruction  of  pathogenic  bacteria,  or  any 
application  of  the  copper  sulphate  method,  which  has  to  do  with  the  public  health 
is  not  contemplated  or  indeed  possible  by  this  Department.  The  requests  of  pri- 
vate individuals  or  of  unauthorized  bodies  for  information  or  assistance  can  not  be 
granted.  When  State  or  local  boards  of  health  consider  that  the  disinfection  of  a 
water  supply  is  desirable  and  wish  information  upon  the  subject,  it  will  be  supplied 
as  fully  and  freely  as  possible.  All  experiments  of  this  kind,  however,  must  be 
conducted  by  boards  of  health,  and  the  Department  can  serve  only  in  the  capacity 
of  an  adviser. 

We  are  under  obligation  to  Dr.  H.  P.  Wolcott  and  Mr.  X.  H.  Good- 
nough,  of  the  Massachusetts  State  Board  of  Health,  for  facilities  in 
securing  material  and  a  temporary  laboratory  in  the  Boston  State 
House;  to  the  United  States  Bureau  of  Fisheries  for  fish  used  in 
experiments;  to  Dr.  J.  J.  Kinyoun  for  typhoid  cultures;  to  Dr.  M.  J. 
Rosenau  for  Asiatic  cholera  cultures,  and  to  the  Bureau  of  Animal 
Industry  for  cultures  of  typhoid  and  facilities  for  carrying  on  pre- 
liminary experiments. 

ALBERT  F.  WOODS, 
Pathologist  and  Physiologist. 
OFFICE  OF  VEGETABLE  PATHOLOGICAL 

AND  PHYSIOLOGICAL  INVESTIGATIONS, 

Washington,  D.  C.,  April  30,  1904. 


CONTENTS. 


Page. 

Introduction 1 9 

Microscopical  examination  of  drinking  water 9 

Wide  distribution  of  trouble  caused  by  algse  in  water  supplies 10 

Methods  in  use  for  preventing  bad  effects  due  to  algse 13 

Desirability  of  other  methods 14 

Determination  of  a  physiological  method 15 

Effect  of  copper  sulphate 15 

Method  of  applying  copper  sulphate 25 

Practical  tests  of  the  method 26 

Water-cress  beds 26 

Water  reservoirs 27 

Effect  of  copper  upon  pathogenic  bacteria 28 

Typhoid 28 

Asiatic  cholera  . '. 34 

Comparison  of  effect  of  other  disinfectants 36 

Colloidal  solutions 36 

Conclusions 40 

Necessity  of  knowledge  of  organism  and  condition  in  reservoir 40 

Application  of  method  for  destruction  of  pathogenic  bacteria  not  designed 

to  replace  efficient  means  of  filtration  already  in  use 41 

Medicinal  use 42 

Conditions  under  which  the  Department  of  Agriculture  can  furnish  infor- 
mation and  assistance  in  applying  this  method 42 

Cost 43 

Summary 43 

7 


B.  P.  I.— 108.  V.  P.  P.  I.— 118. 

A  METHOD  OF  DESTROYING  OR  PREVENTING  THE  GROWTH  OF 
ALG^E  AND  CERTAIN  PATHOGENIC  BACTERIA  IN  WATER 
SUPPLIES. 


INTRODUCTION. 

The  necessity  and  importance  of  maintaining  by  every  possible 
means  the  purity  and  wholesomeness  of  public  water  supplies  have 
caused  those  in  authority  to  welcome  a  method  which  would  in  any 
way  serve  as  an  additional  safeguard  against  the  pollution  of  reservoirs 
or  would  prevent  the  bad  effects  produced  by  the  growth  of  algae  and 
similar  organisms.  Although  scientific  men  have  been  investigating 
the  various  problems  involved  for  a  considerable  length  of  time,  it  is 
feared  that  the  public  has  not  always  been  in  sympathy  with  these 
methods,  and  that,  owing  to  the  uncertainty  of  and  disagreement  among 
eminent  authorities,  the  whole  question  of  water  analysis,  both  chem- 
ical and  bacteriological,  has  come  somewhat  into  disrepute. 

MICROSCOPICAL  EXAMINATION  OF  DRINKING  WATER. 

While  the  best  known  cases  of  water  pollution  are  those  due  to  the 
presence  of  typhoid  and  other  germs  which  have  given  rise  to  serious 
epidemics,  there  are  a  vastly  greater  number  of  water  supplies  which 
are  rendered  unfit  for  use,  not  because  they  are  dangerous  to  public 
health,  but  on  account  of  the  very  offensive  odor  and  taste  produced 
in  them  by  plants  other  than  bacteria.  For  this  reason,  in  recent 
years,  the  question  of  whether  or  not  a  water  was  fit  to  drink  has  been 
submitted  to  the  biologists  as  well  as  to  the  chemists  and  bacteriol- 
ogists, a  biological  examination  being  generally  understood  to  mean 
the  determination  of  the  character  and  quantity  of  the  microscopical 
plants  and  animals  the  water  may  contain  as  distinct  from  the  bacteria. 

The  history  of  this  method  of  examining  drinking  water  is  really 
confined  to  the  last  quarter  of  the  nineteenth  century,  but  only  within 
ten  or  fifteen  years  have  we  had  any  accurate  knowledge  of  the  effect 
of  these  minute  plants  upon  the  water  in  which  they  live.  It  is  prob- 
able that  Dr.  Hassall,  of  London,  was  the  first  to  publish  any  adequate 
account  of  a  thorough  microscopical  examination  of  any  water  supply, 
and  this  work,  which  appeared  in  1850,  was  practically  the  only  thing 


10         METHOD    OF    DESTROYING    ALG^E    IN    WATER    SUPPLIES. 

upon  the  subject  for  twenty-five  years,  when  "MacDonald's  Guide  to 
the  Examination  of  Drinking  Water"  was  published.  In  the  mean- 
time various  Germans  had  carried  on  investigations  relating  to  the 
biology  of  water  supplies,  notably  Professor  Cohn,  of  Breslau,  who, 
in  a  paper  entitled  the  "Microscopical  Analysis  of  Well  Waters," 
anticipated  much  that  has  since  been  ascertained  in  regard  to  the  effect 
of  environment  upon  the  character  and  quantity  of  the  organism  found 
in  the  water.  About  the  time  of  the  appearance  of  MacDonald's 
book,  interest  in  the  effect  of  algae  in  drinking  water  first  began  to  be 
aroused  in  this  country,  and  papers  by  Farlow"  and  others  called 
attention  to  the  fact  that  these  plants  were  responsible  for  many  of 
the  disagreeable  odors  and  tastes  in  water  reservoirs.  By  the  year 
1878  there  was  on  record  a  list  of  over  60  cities  and  towns  in  the 
United  States  which  had  had  serious  trouble  because  of  the  presence 
of  certain  forms  of  vegetation  in  their  reservoirs,  but  since  then  thou- 
sands of  water  supplies  throughout  the  country  have  been  rendered 
unfit  for  use  by  this  cause  alone.  Early  in  the  year  1891  the  special 
report  upon  the  examination  and  purification  of  water  by  the  Massa- 
chusetts State  Board  of  Health  was  published,  this  being  the  most  com- 
plete treatment  of  the  subject  which  had  appeared  up  to  that  time. 
This  report  has  been  supplemented  by  further  investigations  and 
experiments,  and  the  work  accomplished  by  this  board  in  perfecting 
methods  for  insuring  a  pure  water  supply  has  established  the  standard 
both  in  this  country  and  abroad  for  similar  lines  of  investigation. 

WIDE  DISTRIBUTION  OF  TROUBLE  CAUSED  BY  ALG^E  IN  WATER 

SUPPLIES. 

In  order  to  demonstrate  the  very  wide  distribution  of  the  trouble 
caused  by  algae  in  water  supplies  throughout  the  United  States,  a 
circular  letter  was  sent  to  about  five  hundred  of  the  leading  engineers 
and  superintendents  of  water  companies,  asking  for  information  in 
regard  to  the  deleterious  effects  produced  by  plants  other  than  bacteria 
in  water  supplies  with  which  they  were  familiar.  Many  instructive 
replies  were  received,  indicating  that  those  in  authority  were  extremely 
anxious  to  be  provided  with  some  efficient  remedy  for  preventing  the 
bad  odors  and  tastes  in  drinking  water,  and  that  they  considered  the 

«  FARLOW.  Reports  on  Peculiar  Condition  of  the  Water  Supplied  to  the  City  of 
Boston.  Report  of  the  Cochituate  Water  Board,  1876. 

Reports  on  Matters  connected  with  the  Boston  Water  Supply.     Bulletin 
of  Bussey  Inst.,  Jan.,  1877.. 

Remarks  on  Some  Algae  found  in  the  Water  Supplies  of  the  City  of  Boston, 

1877. 

•    On  Some  Impurities  of  Drinking  Water  Caused  by  Vegetable  Growths. 
Supplement  to  1st  Ann.  Rept.  Mass.  State  Board  of  Health.     Boston,  1880. 

Relations  of  Certain  Forms  of  Algae  to  Disagreeable  Tastes  and  Odors. 

Science,  II,  333,  1883. 


WIDE    DISTRIBUTION    OF   TROUBLE    CAUSED    BY    ALG^E.  11 

subject  worthy  of  most  careful  investigation.  Quotations  from  some 
of  the  letters  received  are  given,  but,  because  there  might  be  some 
objection  to  the  naming  of  towns,  only  the  State  in  which  the  trouble 
occurred  is  indicated.  This  is  sufficient,  however,  to  show  that  the 
difficulty  is  not  confined  to  any  one  part  of  the  country,  and  that  it  is 
the  algae  alone  which  are  responsible  for  most  of  the  bad  odors  and 
tastes  reported. 

CALIFORNIA: 

Any  efforts  in  the  direction  of  preventing  the  growth  of  algae  will  be  gratefully 
acknowledged.     So  long  as  the  growth  is  healthy  it  is  a  benefit,  but  as  soon  as 
the  algae  break  up  then  trouble  begins. 
COLORADO: 

We  have  a  reservoir  of  water  that  has  recently  become  affected  through  the 
presence  of  micro-organisms  of  the  algae  type  that  impart  to  the  water  a  dis- 
agreeable fishy  odor  and  render  its  use  objectionable. 
DELAWARE: 

A  fishy  taste  and  odor. 
ILLINOIS: 

The  water  tasted  and  smelled  like  rotten  wood. 

Trouble  serious  enough  to  cause  general  complaint  by  consumers  on  account 
of  odor  and  taste. 

People  declared  that  the  water  was  musty.     The  appearance  of  the  growth  is 
yellowish-brown,  and  as  nearly  as  I  can  describe  it  the  smell  is  musty.     I  cer- 
tainly think  the  subject  worthy  of  the  best  thought  and  work  the  Government 
can  give  it. 
INDIANA: 

The  growth  increased  to  such  an  extent  that  we  were  compelled  to  cement  the 
bottom  and  5  feet  up  the  sides.  It  was  as  dense  as  a  field  of  clover  in  June. 

Taste  was  said  by  the  people  to  be  woody  or  fishy,  like  rotten  wood  or  decayed 
fish.     At  one  time  the  report  got  out  that  the  body  of  a  missing  man  had  been 
found  in  the  reservoir. 
IOWA: 

After  certain  stages  in  the  alga's  growth  it  seemed  to  die  and  become  decom- 
posed, thus  impregnating  the  water,  giving  it  a  most  unpleasant  odor  and  taste. 
KENTUCKY: 

Fishy  odor  and  taste,  rather  musty. 

The  odor  was  so  strong  that  we  had  to  discontinue  sprinkling  the  streets  and 
lawns. 

Urgency  in  this  case  is  great,  indeed  almost  imperative,  since  the  condition  of 
the  water  during  the  past  two  or  three  summers  has  culminated  in  formal  action 
by  the  authorities. 
MAINE: 

Trouble  to  such  an  extent  as  to  lead  us  to  consider,  without  taking  definite 
action,  whether  or  not  the  water  should  be  filtered  before  being  distributed. 
Odor  is  reported  as  exceedingly  disagreeable,  so  that  many  customers  avoid  the 
use  of  it  as  far  as  possible  and  believe  it  injurious  to  health. 
MASSACHUSETTS: 

Trouble  very  serious;  some  years  water  is  unfit  to  drink.  Present  year  odor 
and  taste  are  not  so  strong  as  last  year,  when  it  was  almost  impossible  to  drink  it. 

The  odor  was  so  bad  that  it  would  be  almost  impossible  to  take  it  as  far  as  the 
mouth  to  taste  it.  Horses  refused  it  at  the  street  watering  troughs  and  dogs  fled 
from  it. 


12         METHOD    OF    DESTROYING    ALG^E    IN    WATER    SUPPLIES. 

MINNESOTA  : 

Water  at  times  a  fishy  odor  or  taste  due  to  decomposed  vegetable  matter. 
Experts  claim  it  is  entirely  harmless. 
NEW  JERSEY: 

Dark  green  gelatinous  substance  in  water,  causing  a  stench  almost  unbearable. 

Have  seen  Uroglena  so  abundant  that  an  odor  could  be  plainly  detected  one- 
third  of  a  mile  away. 
NEW  YORK: 

Water  had  a  very  fishy  taste  and  smell. 

So  very  offensive  as  to  alarm  all  water  takers. 

It  caused  such  a  prejudice  that  the  supply  was  rejected,  although  the  pollution 
was  of  short  duration. 

Strong  fishy  odor  and  taste;  also  odor  of  "smartweed."  Popular  complaint 
was  dead  fish  in  water  mains. 

Odor  and  taste  were  fishy,  popularly  attributed  to  dead  fish;  but  this  is  absurd, 
as  the  Odor  is  that  of  live  fish. 

Odor  pondy  and  fishy;  bad  water;  publicly  condemned.  Board  of  health 
interfered,  yet  analysis  showed  that  water  was  notunhealthful. 

Very  rank,  water  smelled  bad,  particularly  when  warmed.  Tasted  bad,  but 
not  injurious  to  health.  Looked  better  than  tasted  or  smelled. 

Water  became  unfit  for  use,  musty  or  cucumber  taste  and  smell,  odor  very 
strong  in  hot  \vater;  water  became  slimy,  making  it  exceedingly  hard  to  filter. 
Odor  and  taste  at  times  decidedly  fishy.  A  bright  green  powder  seemed  to 
have  been  sprinkled  on  surface. 

I  am  much  interested  to  know  that  you  are  taking  up  an  investigation  of  algae 
and  organisms,  and  I  very  much  hope  you  will  favor  me  with  all  circulars  and 
information  which  you  may  issue  relating  to  the  same.  I  have  not  attempted 
to  fill  out  the  circular  on  the  back  of  your  letter,  but  so  many  cases  of  trouble  of 
this  kind  have  come  to  my  attention  that  any  listing  of  them  would  be  very 
difficult. 

I  am  devoutly  thankful  that  science  in  this  particular  instance  has  got  beyond 
the  pursuit  of  science  for  recreation's  sake  and  is  doing  good  and  endeavoring 
again  directly  to  be  of  much  use  to  mankind.  1  believe  your  work  is  the  first 
done  in  line  of  either  cure  or  prevention  from  algye  conducted  in  a  rational  man- 
ner, or  so  far  as  I  know  even  attempted,  and  I  have  been  connected  with  or  well 
informed  on  public  water  supplies  and  their  management  all  my  professional 
life  of  some  thirty-five  years.  The  worst  case  I  know  of  is  at  the  —  —  reservoir. 
A  special  commission  is  at  this  moment  charged  with  the  duty  of  advising 
whether  or  not  property  worth  some  two  million  dollars  is  to  be  abandoned  on 
account  of  annual  trouble  from  algse. 
OHIO: 

Complaint  from  customers  of  a  fishy  taste  in  water  like  the  slime  from  fresh- 
water fish. 

Water  had  a  fishy  taste,  causing  a  general  kick;  consumers  laid  it  to  the  fish 
in  the  reservoir. 

All  water  drawn  from  house  bibbs  had  an  objectionable  and  strong  odor,  the 
popular  idea  being  that  it  was  due  to  dead  fish. 

The  towns  A —  and  B —  both  have  vile  water,  A —  all  the  year  round,  B —  for 
six  or  eight  weeks  in  the  hottest  part  of  the  summer.     A — 's  water  has  a  vile 
odor,  offensively  musty.     All  vegetables,  cereals,  coffee,  and  such  edibles  and 
drinks  made  with  the  water  are  scarcely  endurable  to  the  visitor. 
PENNSYLVANIA: 

Water  had  a  disagreeable  fishy  odor. 

Water  smelled  and  tasted  as  if  dead  fish  were  in  it. 


METHODS    FOE   PREVENTING    BAD    EFFECTS   DUE   TO    ALGuE.       13 

PENNSYLVANIA — Continued. 

The  growth  affected  the  taste  of  the  water  on  boiling,  but  was  not  regarded  as 
dangerous  to  health. 

A  very  fishy  taste  and  smell.     I  have  been  unable  to  locate,  but  had  an  idea  it 
came  from  vegetation. 

The  water  during  the  autumn  is  so  foul  in  taste  and  odor  that  it  was  necessary 
to  shut  off  the  supply.     The  odor  is  similar  to  that  of  decayed  fish. 

The  first  season  of  using  reservoir  the  water  became  so  fishy  that  it  was  almost 
unfit  for  use.     Since  that,  owing  to  our  care  of  reservoir,  we  have  had  no  trouble 
whatever. 
TEXAS: 

At  this  time  of  the  year  algae  are  fierce;  some  days  we  are  on  top  and  some 
days  the  algae  are  on  top.     Costs  us  an  average  of  $25  a  month  for  cleaning  out 
algae  from  two  reservoirs. 
WISCONSIN: 

Universal  complaint,  caused  by  the  odor  and  taste  due  to  algae. 

METHODS  IN  USE  FOB  PREVENTING  BAD  EFFECTS  DTTE  TO  ALG-ffi. 

In  order  to  prevent  the  odors  and  tastes  above  described,'  engineers 
and  those  in  charge  of  water  supplies  have  tried  various  remedies, 
none  of  which  has  been  perfectly  satisfactory.  Since  few  of  the 
algae  can  develop  without  sunlight,  the  most  frequent  recommenda- 
tion has  been  to  cover  the  reservoir,  and  this  method  has  proved  suc- 
cessful in  a  few  instances.  However,  the  expense  involved  is  so  great 
as  to  make  the  remedy  prohibitive  in  most  cases,  and  other  methods 
have  had  to  be  resorted  to.  One  precaution  which  is  now  almost  uni- 
versally recommended  as  a  means  of  preventing  the  growth  of  algae  is 
to  remove  all  the  organic  matter  possible  from  the  reservoir  and  to  keep 
the  source  of  supply  as  free  as  can  be  from  dead  and  decaying  animal 
and  vegetable  matter.  In  one  notable  instance  millions  of  dollars 
have  been  spent  in  the  removal  of  earth  and  the  substitution  of  gravel 
at  the  bottom  of  an  immense  new  reservoir.  It  remains  to  be  seen, 
however,  whether  this  will  be  sufficient  to  insure  permanent  freedom 
from  these  troublesome  plants.  It  is  certain  that  attempts  of  this 
kind  will  delay  the  appearance  of  algae  in  quantity,  and,  wherever  it 
is  possible  to  do  so,  every  effort  should  be  made  not  only  to  clean  up 
the  reservoir  at  the  time  of  its  construction,  but  to  keep  it  as  free  as 
possible  from  organic  matter  after  it  is  filled.  In  addition  to  cleanli- 
ness a  direct  pumping  system  with  duplicate,  in  case  of  breakdown  or 
repairs,  has  often  been  recommended  for  use  with  ground  water, 
which  usually  produces  a  more  luxuriant  growth  of  algae  and  similar 
organisms  than  surface  water.  Where  it  has  been  necessary  to  store 
such  water,  it  has  been  advisable  to  limit  the  capacity  of  the  reservoir, 
and  frequently  this  storage  is  only  intended  to  be  used  in  case  of  fire. 
Even  so,  the  cleansing  of  the  reservoir  and  the  frequent  flushing  of 
the  water  mains  has  been  considered  necessaiy.  In  storing  surface1 
water  subdividing  the  reservoir  is  occasional^  resorted  to,  and  means 


14        METHOD    OF    DESTROYING    ALGJE    IN    WATEK    SUPPLIES. 

of  obtaining  frequent  agitation  are  introduced  wherever  possible. 
The  pumping  of  air  into  water  or  aerating  it  by  means  of  a  spraying 
apparatus  is  often  of  considerable  value  in  removing  foul  gases  which 
may  be  in  solution,  but  the  effect  of  aeration  upon  the  growth  of  algae 
in  a  reservoir  has  been  very  much  overestimated,  in  some  cases  the 
quantity  being  actually  increased  by  this  means. 

The  filtration  of  water,  both  mechanically  and  by  sand,  which  has 
proved  so  effective  for  the  removal  of  pathogenic  bacteria,  has  been 
recommended  as  a  means  of  removing  the  odors  and  tastes  caused  by 
algae,  but  the  results  obtained  have  not  given  promise  of  success. 
Perhaps  the  most  careful  experiments  to  determine  this  point  have 
been  conducted  by  those  in  charge  of  the  Ludlow  reservoir  at  Spring- 
field, Mass.  Here  the  annual  trouble  from  algae  for  the  past  fifteen 
years  has  been  so  great  that  every  possible  means  has  been  used  which 
offered  any  relief  from  the  effects  produced  by  these  plants.  On  page 
4  of  the  ".Special  Report  on  the  Improvement  of  the  Present  Water 
Supply  and  an  Alternative  New,  Independent  Supply,"  made  by  the 
board  of  water  commissioners  to  the  city  council  of  the  city  of  Spring- 
field, Mass.,  April  14,  1902,  the  following  statement  is  made: 

We  find,  as  the  results  of  the  experiments  of  filtration,  made  with  the  sanction  of 
your  honorable  body  during  the  last  fifteen  months,  that  to  purify  the  waters  of  this 
source  by  filtration  would  be  not  only  doubtful  as  to  the  degree  of  purification,  but 
so  expensive  in  the  cost  of  construction  and  perpetual  maintenance  thereafter  as 
to  make  it  inexpedient  to  attempt  improvement  by  such  a  method.  Your  board  has 
given  constant  and  personal  attention  to  the  experimental  work,  and  is  convinced 
that  the  excessive  growths  of  obnoxious  fresh-water  organisms,  notably  the  Ana- 
baena,  impart  to  the  reservoir  such  rank  and  persistent  tastes  and  odors  as  to  make 
uncertain  entire  removal  by  any  method  of  filtration  except  that  of  the  expensive 
kind,  applicable  only  to  the  filtering  of  extremely  small  quantities  of  water,  and 
requiring  constant  attention  and  adjustment. 

The  State  board  of  health,  in  a  special  report  (p.  84)  submitted  at  the 
same  time,  say  that  the  results  of  the  experiments  indicate,  in  the 
opinion  of  the  board,  that  by  double  filtration  it  will  be  possible  to 
purify  the  Ludlow  reservoir;  hence  there  seem  to  be  differences  of 
opinion  as  to  the  value  of  this  treatment  for  the  removal  of  odors  and 
tastes,  but  on  account  of  the  expense  involved  there  is  not  likely  to  be 
any  very  extensive  use  of  this  method. 

DESIRABILITY   OF   OTHER  METHODS. 

While  each  of  the  above-mentioned  methods  has  been  used  with 
some  success,  it  is  generally  conceded  by  engineers  that  there  is  no 
known  remedy  which  is  universally  applicable.  It  is  the  practice 
of  some  of  the  highest  authorities  to  recommend  that  reservoirs  f re- 
quentty  polluted  by  algae  be  abandoned,  and  steps  taken  to  provide  an 
entirely  new  system  of  supply.  This  is,  of  course,  the  last  resort,  as 
in  all  such  cases  a  large  loss  of  money  is  involved.  One  fact  is  certain. 


DETERMINATION    OF    A    PHYSIOLOGICAL    METHOD.  15 

If  any  known  method  of  preventing  the  growth  of  algae  was  considered 
truly  effective,  it  would  under  all  circumstances  be  recommended. 

Because  of  the  unsatisfactory  results  or  the  prohibitive  expense  of 
the  present  methods  recommended  for  ridding  reservoirs  of  algae,  it 
seemed  advisable  that  the  problem  be  taken  up  from  an  entirely  new 
standpoint,  one  that  would  take  into  consideration  the  biological  aspect 
of  the  question  and  perhaps  furnish  a  solution,  through  a  study  of  the 
physiology  of  the  organisms  under  laboratory  conditions.  A  series  of 
investigations  were  therefore  undertaken  to  discover,  if  possible,  some 
substance  which,  because  of  its  extreme  toxic  effect  upon  the  alga3 
involved,  would  absolutely  prevent  their  growth  in  water  supplies. 

DETERMINATION  OF  A  PHYSIOLOGICAL  METHOD. 

In  determining  such  a  physiological  method  of  dealing  with  reser- 
voirs contaminated  by  algaer  two  conditions  had  to  be  considered:  The 
remedy  should  not  only  be  readily  available  and  cheap  enough  for 
practical  use  in  the  largest  reservoirs  and  by  the  poorest  communities, 
but  under  the  conditions  used  it  must  also  be  absolutely  harmless  to 
man ;  the  maximum  amount  necessary  to  kill  the  algae  being  far  below 
the  amount  which  could  in  any  way  affect  the  consumer  of  the  water. 
Of  the  large  number  of  substances  experimented  with,  few  gave  en- 
couraging results.  Free  chlorine  at  a  dilution  of  1  to  10,000,  and  sul- 
phur dioxide  in  saturated  aqueous  solution  at  16°  C.,  diluted  1  to  1,000 
and  to  10,000,  will  destroy  many  of  the  common  forms  of  algae,  but  sul- 
phur dioxide  and  chlorine  are  likewise  very  injurious  to  animal  life. 
Silver  has  a  very  high  toxicity,  and  were  not  the  expense  prohibitive, 
would  undoubtedly  warrant  extended  tests.  Mercury  and  lead  are, 
of  course,  out  of  the  question,  and  zinc  requires  too  high  a  concentra- 
tion to  be  practically  considered.  The  ordinary  sodium,  potassium, 
and  ammonium  salts,  are  innocuous,*  as  are  most  of  the  acids.  Loew6 
finds  that  magnesium  sulphate  is  toxic  in  pure  solution  at  0.4  per  cent, 
and  that  oxalates  are  slightly  more  toxic;  of  the  acids,  0.0001  per  cent 
oxalic  kills  most  of  the  cells  of  Spirogyra  majuscula  in  five  days. 
Migula  c  notes  the  effect  of  many  of  the  organic  acids,  but  the  use  of 
these  substances  in  the  amounts  requisite  for  treating  a  contaminated 
water  supply  is  entirely  impracticable. 

EFFECT  OF  COPPER  SULPHATE. 

Reviewing  the  experiments  carried  on  in  the  Laboratory  of  Plant 
Physiology,  as  well  as  the  results  obtained  by  other  investigators,  it 

«Cf.  Richter,  Flora,  75:  4. 
&Loew,  Flora,  75:  368. 

c  Migula,  Ueber  den  Einfluss  stark  verduenter  Sauren  auf  Algenzellen,  Breslau, 
1888.     ( Original  not  consulted. ) 
28480— No.  64—04 2 


16         METHOD    OF    DESTROYING    ALG^E    IN    WATER    SUPPLIES. 

seems  that  copper  sulphate  is  the  substance  best  adapted  to  the  work 
in  question.  This  salt  has  a  very  high  toxicity  for  algae,  and  experi- 
ments with  a  number  of  the  forms  usually  found  in  reservoirs,  and 
the  source  of  much  trouble,  have  shown  that  inconceivably  small 
amounts  of  copper  are  poisonous  in  a  high  degree.  These  experiments 
demonstrated,  however,  that  all  algae  and  protozoa  are  not  equally  sen- 
sitive. Among  the  latter  Params&dum  is  killed  in  three  hours  by  a  1 
to  1,000,000  solution,  while  A.?nceba,  Diffiugia,  and  Spi/rost&mum  die 
within  two  hours.  Crustacea  are  more  resistant,  some — Cypris  and 
Daphnia  especially — requiring  as  much  as  1  part  copper  sulphate  to 
10,000  of  water  to  kill  them.  Mosquito  larvae  die  at  a  concentration 
varying  from  10,000  to  200,000. 

Quoting  the  results  of  other  experimenters,  Devauxa  found  that 
both  phaenogams  and  cryptogams  were  poisoned  by  solutions  of  copper 
diluted  to  the  ten-millionth  part  or  less;  Coupin&  that  1  part  copper 
sulphate  to  700,000,000  of  water  was  sufficient  to  affect  the  growth  of 
seedlings  when  applied  to  their  roots  and  that  this  is  the  most  inju- 
rious of  the  heavy  metal  salts  tested  by  him;  Deherain  and  De  Moussy  c 
that  the  development  of  the  roots  of  seedlings  was  arrested  in  distilled 
water  containing  the  slightest  trace  of  copper,  and  they  conclude  from 
this  that  higher  plants  during  germination,  as  well  as  fungi  and  algy?, 
are  extremely  sensitive  to  copper;  Bain's  experiments  d  indicated  that 
1  part  of  metallic  copper  to  25,000,000  of  water  was  fatal  to  apple  seed- 
lings in  one  day;  on  the  other  hand,  according  to  Raulin/  copper  chlo- 
ride does  not  injure  Sterigmatocystis  until  a  concentration  of  1  to  240  is 
reached,  although  silver  nitrate  is  toxic  at  1  to  1,600,000. 

In  dealing  with  algae,  the  toxic  concentration  varies  greatly  for  dif- 
ferent genera,  even  for  different  species  in  the  same  genus.  Nageli; 
demonstrated  the  extreme  sensitiveness  of  Splrogyra  nitida  and  S. 
diibia  to  the  presence  of  copper  coins  in  the  water.  Oscillatoria, 
Cladophora,  (Edog&nium,  and  the  diatoms  succumb  in  six  hours 
to  a  copper  sulphate  solution  of  1  to  20,000,  and  in  two  days  to  1  to 
50,000,  according  to  Bokorny.*7  GaleottiA  finds  that  a  concentration 
between  1  to  6,300,000  and  1  to  12,600,000  is  sufficient  to  kill  Spiro- 
gyra  nitida  in  two  days,  and  that  the  so-called  colloidal  solutions  at  1 
to  6,300,000  are  fatal  in  the  same  length  of  time;  while  in  the  experi- 

«Devaux,  Compt.  Rend.,  132:  717. 
&Coupin,  Compt,  Rend.,  132:  645. 
^'Deherain  and  De  Moussy,  Compt.  Rend.,  132:  523. 
^Bain,  Bull.  Agr.  Exp.  Sta.  Tenn.,  April,  1902. 
"Raulin,  Ann.  des  So.  Nat.  Bot.,  5C  Ser.,  II:  93. 

/Nageli,    Ueber    oligodynamische    Erscheinungen    in    lebenden    Zellen.     Neue 
Denkschr.  d.  schweizerischen  Gesellsch.  fiir  die  gesammten  Naturwiss.,  33:  51. 
r/Bokorny,  Arch.  f.  d.  ges.  Phys.  d.  Mensch.  u.  Thiere,  64:  262. 
''Galeotti,  Biol.  Centralbl.,  21:  321. 


EFFECT  OF  COPPER  SULPHATE.  17 

ments  of  Israel  and  Klingman  a  the  presence  of  60  sq.  cm.  of  copper 
foil  in  300  cc.  of  water  for  twenty-four  hours  produced  plasinal  cut- 
ting in  S.  laxa  after  one  and  one-fourth  hours,  in  S.  crassa  after  fifteen 
minutes,  and  in  S.  majuscula  after  thirty  minutes.  The  work  of 
Rumm6  shows  1  to  10,000,000  solution  still  toxic  to  a  few  more  sus- 
ceptible cells  of  S.  longata.  According  to  Ono, c  weak  solutions  of  the 
salts  of  most  of  the  metals  encourage  the  growth  of  algae  and  fungi. 
Mercury  and  copper,  however,  at  0.00005  per  cent  and  0.00001  per 
cent,  respectively,  distinctly  inhibit  growth.  This  was  the  case  with 
Stigeoclonium,  Chroococcum,  and  Protococcus. 

In  the  experiments  conducted  in  this  laboratory  it  has  not  been  pos- 
sible as  yet  to  include  all  of  the  organisms  known  to  pollute  water 
supplies.  It  is  believed,  however,  that,  pending  the  completion  of 
more  extensive  work,  the  data  at  hand  will  be  of  considerable  benefit 
to  those  who  have  to  deal  with  contaminated  reservoirs.  The  method 
of  procedure  in  studying  this  question  was  to  determine  roughly  the 
death  points  of  the  forms  under  consideration,  using  Van  Tieghem  cells. 
Accurate  solutions  were  then  made,  with  distilled  water,  and  200  cc. 
of  each  solution  was  pipetted  into  an  Erlenmyer  flask.  The  algae,  if 
filamentous  forms,  were  rinsed;  if  free-swimming,  they  were  concen- 
trated b}^  the  Sedgwick-Raf ter d  method  from  500  cc.  to  5  cc.  volume, 
and  this  5  cc.  was  added  to  the  treated  water.  The  inaccuracy  due  to 
the  addition  of  the  5  cc.  of  untreated  water  to  the  200  cc.  of  treated 
water  was  disregarded.  Whenever  possible,  a  test  of  these  concen- 
trations, determined  experimentally,  was  made  under  natural  conditions 
by  treating  the  pool  from  which  the  species  under  consideration  was 
taken.  If  this  was  impracticable,  an  additional  series  was  carried 
through  in  aquaria  of  15  liters  capacity,  in  which  were  kept  goldfish, 
frogs,  minnows,  Crustacea,  and  rotifers.  Since  in  no  case  was  there 
an  appreciable  difference  in  the  effect  of  a  concentration  upon  a  par- 
ticular organism  under  either  natural  or  artificial  conditions,  no  special 
record  is  made  of  these  gross  experiments. 

The  different  species  tested  may,  for  convenience,  be  grouped  as  (1) 
those  with  death  points  at  higher  concentrations  than  1  part  copper 
sulphate  to  1,000,000  parts  of  water;  (2)  those  with  death  points  between 
1  to  1,000,000  and  1  to  5,000,000;  and  (3)  those  with  death  points  at 
greater  dilutions  than  1  to  5,000,000. 

« Israel  and  Klingman,  Virchow's  Archiv.,  147:  293. 

6  Rumm,  Beitrage  zur  Wissenschaftliche  Botanik,  1 :  97. 

fOno,  Journ.  of  College  of  Sc.,  Imp.  Univ.  Tokyo,  13:  141. 

d  Whipple,  The  Microscopy  of  Drinking  Water,  New  York,  1899,  p.  15. 


18 


METHOD    OF    DESTROYING    ALG^E    IN    WATER    SUPPLIES. 


Effect  of  various  concentrations  of  copper  sulphate  upon  different  forms  ofalgx. 
[d=dead;  vfa=very  few  alive;  vfd=very  few  dead;  g=in  good  condition.] 

GOROTJIP  1. 
CHLAMYDOMONAS  PIRIFORMIS  Dill. 


Date. 

One  part  copper  sulphate  to  water,  parts  — 

Check. 

2,000 

5,000 

10,000 

20,000 

200,000 

1,000,000 

October  19-21  

id 
^d 
id 

g 
vfd 
yfd 

g 
g 
g 

g 
g 
g 

g 
g 
g 

g 
g 
g 

g 
g 
g 

October  21-24 

October  24-27  

RAPHIDIUM  POLYMORPHUM  Fres. 


Date. 

One  part  copper  sulphate  to  water,  parts— 

Check. 

25,000 

50,000 

75,000 

100,000 

500,000 

1,000,000 

October  19-29 

d 
d 
d 

d 
*d 
vfa 

id 
id 
id 

iVd 

&d 

vfd 

g 
g 
g 

g 
g 
g 

g% 
g 
g 

November  2-6 

November  16-20  

DESMIDIUM  SWARTZII  Ag. 


Date. 

One  part  copper  sulphate  to  water,  parts  — 

Check. 

50,000 

75,000 

100,000 

150,000 

200,000 

1,000,000 

December  2-5 

d 
d 

d 
d 

id 
Id 

vfd 
vfd 

g 
g 

g 
g 

g 
g 

January  4-7  

STIGEOCLONIUM  TENUE  (Ag.)  Rabenh. 


Date. 

One  part  copper  sulphate  to  water,  parts— 

Check. 

50,000 

100,000 

300,000 

500,000 

1,000,000 

2,000,000 

December  21-24 

id 
id 
id 

id 
id 
id 

id 
id 
id 

id 
id 
id 

vfd 
vfd 
vfd 

g 
g 
g 

g 
g 
g 

January  2-5  

January  7-11 

DRAPARNALDIA  GLOMERATA  (Vauch.)  Ag. 


Date. 

One  part  copper  sulphate  to  water,  parts— 

Check. 

50,000 

100,000 

300,000 

500,000 

1,000,000 

2,000,000 

December  1-8 

id 

id 

id 

id 

vfd 

g 

g 

NAVICULA  Sp. 


Date. 

One  part  copper  sulphate  to  water,  parts  — 

Check. 

100,000 

200,000 

300,000 

400,000 

500,000 

1,000,000 

October  20-25  

d 
d 

d 
vfa 

id 
id 

vfd 
vfd 

vfd 
vfd 

g 
g 

id 
g 

January  4-9 

EFFECT  OF  COPPER  SULPHATE.  19 

Effect  of  various  concentrations  of  copper  sulphate  upon  different  forms  of  algse — Cont'd. 

GKROTJIP  1— Continued. 
SCENEDESMUS  QUADRICAUDA  (Turp.)  Breb. 


Date. 

One  part  copper  sulphate  to  water,  parts— 

Check. 

100,000 

200,000 

300,000 

400,000 

500,000 

1,000,000 

September  14-18 

d 
d 
vfa  . 

d 
vfa 
vfa 

vfa 
vfa 
vfa 

id 
id 
id 

g 
g 
g 

g 
g 
g 

g 
g 
g 

December  7-12  

January  11—15 

EUGLENA  VIRIDIS  Ehrb: 


Date. 

One  part  copper  sulphate  to  water,  parts— 

Check. 

100,000 

200,000 

300,000 

400,000 

450,000 

500,000 

September  21-25 

d 
vfa 
vfa 

vfa 
vfa 

vfa 

vfa 
vfa 
vfa 

Id 
*d 
id 

id 
id 
id 

g 
g 
g 

g 
g 
g 

October  26-30                     

December  31-January  2  

SPIROGYRA  STRICT  A  (E.  Bot.)  Wille. 


Date. 

One  part  copper  sulphate  to  water,  parts  — 

Check. 

50,000 

75,000 

100,000 

200,000 

500,000 

1,000,000 

December  26-30 

d 

vfa 

*d 

g 

g 

g 

g 

GKROTJP  2. 

CONFERVA  BOMBYCINUM  Ag. 


One  part  copper  sulphate  to  water,  parts — 


50,000 

100,000 

300,000 

500,000 

1,000,000 

2,000,000 

<jnecjt. 

October  l^i 

d 

d 

d 

d 

d 

g 

October  8-11.               

d 

d 

d 

vfa 

vfa 

g 

October  13-17  

d 

d 

d 

vfa 

vfa 

g 

g 

CLOSTERIUM  MONILIFERUM  (Bory  )  Ehrb. 


i 
Date. 

One  part  copper  sulphate  to  water,  parts  — 

Check. 

25,000 

100,000 

500,000 

1,000,000 

2,000,000 

December  14-18 

dl2hrs 

d24hrs 

d 

d 

id 

g 

SYNURA  UVELLA  Ehrb. 


Date. 

One  part  copper  sulphate  to  water,  parts— 

Check. 

250,000 

500,000 

606,666 

750,000        1,000,000 

2,500,000 

Marchl4  

d5-25min 
d6-25min 

d!5-30min 
dl5-30min 

d!5-45min 
d  15-45min 

d  15-60min  d  28-60min 
d  15-60min  d  28-60min 

g  at  Ihr 
g  at  Ihr 

gat  Ihr 
gat  Ihr 

March  18 

20        METHOD    OF   DESTKOYING    ALGJE   Itf   WATER   SUPPLIES. 

Effect  of  various  concentrations  of  copper  sulphate  upon  different  forms  of  algx — Cont'd. 

G-ROUF   3— Continued. 
ANAByENA  CIRCINALIS  Raben, 


Date. 

One  part  copper  sulphate  to  water,  parts  — 

Check. 

50,000 

100,000 

500,000 

1,000,000 

8,000,000 

5,000,000 

December  26-29  

d 
d 

d 
d 

d 
d 

d 
d 

id 
id 

vfd 
vfd 

g 
g 

January  4—7 

ANAB^NA  FLOS-AQU^E  Breb. 


Date. 

One  part  copper  sulphate  to  water,  parts  — 

Check. 

50,000 

100,000  530,000 

1,000,000 

3,000,000 

5,000,000 

July  12-14 

d  12hrs 
d  12hrs 

d24hrs  d  24hrs 
d24hrs  d  24hrs 

d36hrs 
d  36hrs 

d  72hrs 
d  72hrs 

-id 
id 

g 
g 

August  27-29  

3. 

UROGLENA  AMERICANA  Calk. 


Date. 

One  part  copper  sulphate  to  water,  parts  — 

Check. 

1,000,000 

2,500,000 

5,000,000 

10,000,000 

March  19, 

1903 

d  3-5min 

d  IGhrs 

vfa  IGhrs 

yfa  16hrs 

g 

The  foregoing  tables  clearly  demonstrate  the  effectiveness  of  copper 
sulphate  as  an  agent  for  the  destruction  of  algae,  and  as  the  cost 
for  an  amount  of  this  salt  necessary  to  make  the  strongest  solution 
required  will  not  exceed  from  50  to  60  cents  per  million  gallons,  but 
one  condition  remains  to  be  satisfied — that  it  shall  be  absolutely  harm- 
less to  man,  domestic  animals,  and  fish  under  the  conditions  used. 

In  general,  animal  life  is  less  susceptible  to  injury  by  copper  than  is 
plant  life,  though  most  of  the  higher  plants,  some  of  the  fungi,  and, 
as  the  preceding  tables  show,  certain  alga?  will  live  in  concentrations 
of  copper  suFphate  that  would  be  fatal  in  a  few  hours  to  fish  and  frogs. 
The  critical  concentration  for  game  fish  is  higher  than  that  for  such 
fish  as  carp  and  catfish.  Black  bass  in  good  condition  have  endured 
concentrations  of  1  to  50,000  for  many  weeks  with  no  apparent  discom- 
fort, while  1  to  100,000  was  sufficient  to  kill  German  and  mirror  carp 
in  a  few  hours,  and  1  to  500,000  killed  the  most  susceptible  in  a  few 
days.  Mud  catfish  are  affected  at  practically  the  same  concentration; 
goldfish  at  slightly  greater,  while  yellow  perch  are  perhaps  Jess  sus- 
ceptible than  goldfish.  This  agrees  with  the  results  of  Perry  and 
Adams, a  who  state  that  minnows  and  goldfish  live  indefinitely  in  a  1 
to  200,000  solution.* 


«  Perry  &  Adams,  4th  Kept.  River  Polut.  Conn.,  2:  377-391. 


EFFECT  OF  COPPER  SULPHATE.  21 

The  effects  of  copper  upon  the  higher  animals  have  been  studied  by 
a  large  number  of  investigators,  and  the  following  results  may  be 
appropriately  cited: 

Metallic  copper  and  its  oxides,  mixed  with  sugar,  albuminoids,  and 
fats,  had  no  noticeable  effect  upon  dogs;  even  8  grams  of  fine  powder 
(4  grains  each  of  copper  monoxide  and  dioxide)  caused  only  a  slight  sick- 
ness. Verdigris  in  small  amounts  produced  none  of  the  violent  results 
it  is  supposed  to  cause  in  man.  Soluble  salts  of  copper  can  be  given  in 
quantities  up  to  1  gram  daily,  but  more  than  this  has  a  fatal  effect.08 

Dogs  that  had  eaten  half  a  gram  of  copper  acetate  per  day  for  24 
days  suffered  but  slightly;  one  dog  was  unaffected  by  doses  as  high  as 
5  grams  at  a  time.6  Similar  results  were  obtained  by  Du  Moulin, c  who 
gave  dogs  and  rabbits  as  much  as  3  to  5  grams,  causing  sickness  but 
in  no  case  death,  and  Hippolyte  Kuborn  d  states  that  a  dog  can  take  4 
grams  of  copper  sulphate  with  but  slight  effect. 

Ellenberger  and  Hofmeister e  experimented  with  sheep,  giving  them 
from  18  to  182i  grams  of  copper  in  quantities  sometimes  as  large  as 
2  grams  per  day,  with  fatal  results.  Tschirsch^  deduced  from  this  that 
the  nontoxicity  of  weak  solutions  of  copper  does  not  hold  for  rumi- 
nants, but  this  seems  hardly  warranted.  Two  grams  per  day  can 
scarcely  be  considered  a  small  amount,  yet  one  sheep  lived  53  days 
and  the  other  128. 

Ever  since  copper  compounds  have  come  into  general  use  as  fungi- 
cides, the  question  as  to  their  effect  upon  the  human  system  has 
received  more  or  less  attention.9'  At  times  there  have  been  vague 
and  misleading  statements  in  the  public  press,  calculated  to  alarm 
those  who  are  in  the  habit  of  using  vegetables  and  fruits  which  have 
been  subjected  to  treatment  with  Bordeaux  mixture.  The  popular 
belief  seems  to  be  that  copper  is  a  poison,  but  it  is  found  upon  exami- 
nation that  the  very  best  authorities  are  by  no  means  agreed  upon  this 
point.  It  is  true  that  after  the  question  had  been  discussed  for  seven 
months  before  the  Belgian  Royal  Academy  of  Medicine,  in  1885,  it 
was  finally  decided  that  copper  compounds  in  foods  were  harmful,  but  it 
should  be  remembered  that  in  the  whole  discussion,  where  every  effort 
was  made  by  one  side  to  show  that  copper  was  an  actual  poison,  not  a 

«Burcq  &  Ducom,  Journal  de  Pharmacie  et  Chimie,  25:  546,  1877. 

&  Galippe,  Journal  de  Pharmacie  et  Chimie,  23 :  298. 

c  Du  Moulin,  Journal  de  Pharmacie  et  Chimie,  5 :  189. 

d  Hippolyte  Kuborn,  Congres  Internationale  d'Hygiene,  2:  216,  1878. 

«  Ellenberger  and  Hofmeister,  Archiv  fur  wissench.  u.  prakt.  Thierheilkunde,  9: 
325,  1883. 

/  Tschirsch,  Das  Kupfer  vom  Standpunkte  der  gerichtlichen  Chemie,  Toxicologie 
und  Hygiene,  Stuttgart,  1893. 

Q  Spraying  Fruits  for  Insect  Pests  and  Fungous  Diseases,  with  a  Special  Consider- 
ation of  the  Subject  in  Its  Relation  to  the  Public  Health.  TJ.  S.  Department  of 
Agriculture,  Farmers'  Bulletin  No.  7,  1892.  See  also  Bull.  No.  6,  Div.  Veg.  Path., 
U.  S.  Dept.  Agric. 


22         METHOD    OF    DESTROYING    ALG.E   IN    WATER   SUPPLIES. 

single  instance  was  given  of  injury  to  health  resulting  from  the  daily 
absorption  of  a  small  quantity  of  copper.  On  the  other  hand,  many 
instances  were  cited  where  foods  containing  copper  in  considerable 
amounts  were  used  without  producing  any  harmful  effect  whatever. 
It  should  be  noted  also  that  the  law  prohibiting  the  use  of  copper  in 
regreening  fruits  was  repealed  by  the  French  authorities  after  the  dis- 
cussion before  the  Belgian  Academy. 

According  to  Thiemann-Gartner,ff  chronic  copper  poisoning  has 
never  been  proved.  The  supposed  copper  colic  was  discussed  by 
Burcq&  before  the  Congres  Internationale  d'Hygiene  in  1878,  and 
declared  by  him  to  have  no  existence;  he  even  went  so  far  as  to  assert 
an  immunity  against  cholera  for  the  workers  in  copper  during  various 
epidemics  at  Paris,  Toulon,  Marseilles,  and  elsewhere,  but  this  state- 
ment he  afterwards  modified  with  reference  to  the  epidemic  of  1832. 
The  good  health  of  copper  workers  is  also  noted  by  Houles  and 
Pietra-Santa,c  though  they  do  not  claim  for  them  immunity  from 
typhoid  and  cholera.  Gautier^  states  that  persons  working  in  dye 
factories,  where  the  hands,  faces,  and  even  hair  were  colored  green  by 
copper,  were  pl^sically  unaffected,  which  is  true  also  of  copper 
turners,  who  remain  apparently  in  the  best  of  health  although  con- 
stantly in  an  atmosphere  highly  charged  with  copper  dust. 

A  considerable  number  of  experiments  have  been  made  to  determine 
the  effect  of  copper  upon  man  when  taken  into  the  intestinal  tract. 
For  fourteen  months  Galippe e  and  his  family  used  food  cooked  and 
cooled  in  copper  vessels,  the  amount  of  copper  present  in  the  food 
being  sufficient  to  be  easily  determined.  Robert's  experiments^  show 
that  a  60-kg.  man  can  take  1  gram  of  copper  per  day  with  perfect  safety. 
From  his  own  results  Lehmann^  considers  that  copper  to  the  amount 
of  0.1  gram  in  vegetables  may  produce  bad  taste,  nausea,  possibly 
colic  and  diarrhea,  but  nothing  more  serious.  He  has  himself  found 
peas  containing  as  much  as  630  mg.  of  copper  per  kilogram  not  dis- 
tasteful, and  200  mg.  consumed  at  a  single  meal  was  without  effect. 
A  very  careful  and  thorough  series  of  tests  have  shown  that  some 
individuals,  at  least,  can  take  copper  even  to  the  amount  of  400  to 
500  mg.  daily  for  weeks  without  detriment  to  their  health. 

Tschirsch^  finds  that  0.01  to  0.02  of  copper  (0.039  to  0.078  of  copper 
sulphate)  in  dilute  form  have  no  effect;  0.05  to  0.2  causes  only  vomit- 
ing and  diarrhea. 

«  Thiemann-Gartner,  Handbuch  und  Beurtheilung  der  Untersuchung  der  Wasser, 
Braunschweig,  1895. 

&Burcq,  Congres  Internationale  d'  Hygiene,  1:  529,  1878. 

«  Houles  and  Pietra-Santa,  Journal  de  Pharmacie  et  Chimie,  5th  Ser.,  9:  303. 

d  Gautier,  Le  Cuivre  et  le  Plomb,  Paris.  1883. 

e Galippe,  Compt.  Rend.,  84:  718. 

/Kobert,  Lehrbuoh  der  Intoxicationen.     (Original  not  consulted.) 

<7Lehmann,  Munch.  Med.  Wochensch.,  38:  603. 

'' Tschirsch,  1.  c. 


UNIVERSI! 


EFFECT   OF   COPPER   SULPHATE. 


The  process  of  regreening  legumes  is  described  by  Bouchardat  and 
Gautier,  a  showing  the  amount  of  copper  thus  introduced  into  the 
vegetables  to  be  too  small  to  produce  any  injurious  effect.  The  maxi- 
mum amount  of  this  metal  in  regreened  peas  as  given  by  Gautier  b  is 
125  mg.  per  kilogram,  in  connection  with  which  he  notes  that  Chatin 
and  Personne  have  given  it  as  270  mg.  According  to  Gautier,  the 
amount  of  copper  ordinarily  consumed  in  a  full  meal  is  95  mg. 

Lafar  c  attributes  the  green  color  of  Lodisan  and  Parmesan  cheese 
to  the  presence  of  copper,  giving  the  maximum  amount  for  Lodisan 
cheese  as  215  mg.  per  kilogram.  Chocolate  d  contains  0.005  to  0.125 
gram  per  kilogram,  cafe  bourbon  e  8  mg.  per  kilogram,  and  beef  1  mg. 
per  kilogram.  There  is  0.01  gram  of  copper  sulphate  in  1£  pounds  of 
bread/  0.1  gram  of  copper  oxide  has  been  found  in  1  kilogram  of  pre- 
serves, and  similar  amounts  are  normally  present  in  a  large  number  of 
commodities  used  for  food. 

Medicinal  uses  of  copper  compounds  are  cited  by  Du  Moulin.^  He 
has  prescribed  12  to  15  eg.  for  scrofulous  children,  for  cases  of  oph- 
thalmia, etc.,  and  found  no  ill  effects.  Copper  sulphate  in  doses  of  40 
to  50  eg.  for  four  or  five  days  has  proved  beneficial  to  children  with 
diphtheria. 

Summarizing  from  a  large  number  of  experiments,  Bernatzik^  con- 
cludes as  follows:  After  entering  the  stomach  only  small  quantities  of 
copper  are  absorbed  by  the  blood,  and  toxic  action  occurs  only  when 
the  necessary  amount  can  accumulate  in  the  circulation.  Silver, 
copper,  and  zinc  have  almost  the  same  medicinal  properties,  the  dif- 
ference being  of  degree  rather  than  kind.  They  differ  markedly  from 
other  heavy  metals,  having  no  harmful  effects  upon  the  tissues,  and 
producing  no  fatal  functional  injuries;  hence  they  are  not  poisons  in 
the  same  sense  as  are  lead,  mercury,  arsenic,  antimony,  and  phos- 
phorus. Moreover,  in  the  case  of  copper,  after  suspension  of  the 
dose  the  injured  functions  return  to  the  normal. 

It  is  evident  that  there  is  still  a  considerable  difference  of  opinion 
among  eminent  authorities  as  to  the  exact  amount  of  copper  which 
may  be  injurious,  but  as  a  very  conservative  limit  we  may  accept  0.02 
gram  as  the  amount  that  may  with  safety  be  absorbed  daily.  Accord- 
ing to  Merck's  Index,  the  National  Dispensatory,  and  the  United 
States  Dispensatory,  the  dose  of  copper  sulphate  for  tonic  and  astrin- 

«  Bouchardat  and  Gautier,  Congres  Internationale  d'  Hygiene,  5:  486. 
6  Gautier,  1.  c. 

c  Lafar,  Technical  Mycology,  159. 
<i  Duclaux,  Bull,  de  la  Soc.  Chim.  de  Paris,  16:  35. 
«Sargeau,  Jour,  de  Pharm.,  18:  219,  654;  16:  507. 
/Tschirsch,  1.  c. 

ffDn  Moulin,  Journal  de  Pharmacie  et  Chimie,  13:  189. 

^Bernatzik,  Encyclop.  d.  ges.  Medicin.,  11:  429;  Encyclop.  d.  ges.  Heilkunde, 
11:  429. 


24         METHOD    OF    DESTROYING    ALG^E    IN    WATER    SUPPLIED. 

gent  purposes  is  one-fourth  grain,  or  0.016  gram;  as  an  emetic,  a  dose 
of  live  grains,  or  0.33  gram.  Thus  it  is  seen  that  even  if  the  maximum 
concentration  of  copper  sulphate  necessary  to  destroy  algae  in  reser- 
voirs were  maintained  indefinitely,  the  total  absorption  from  daily  use 
would  be  very  far  below  an  amount  that  could  produce  the  least 
unpleasant  effect.  Taking  a  dilution  of  one  to  one  million,  which  in 
all  cases  would  be  sufficient  to  prevent  the  growth  of  a  polluting  algal 
form,  it  would  be  necessary  to  drink  something  over  twenty  quarts  of 
water  a  da}7  before  an  amount  which  is  universally  recognized  as 
harmless  would  be  introduced  into  the  system,  while  more  than  fifty 
quarts  would  have  to  be  consumed  before  there  would  be  danger  of 
producing  an  unpleasant  or  undesirable  effect.  As  will  be  seen  from 
the  preceding  tables  the  use  of  copper  sulphate  at  this  maximum 
strength  of  one  to  one  million  would  need  to  be  resorted  to  only  in 
extreme  cases,  and  for  a  very  short  length  of  time,  for,  the  reservoir 
once  entirely  free  from  the  organisms,  a  very  much  weaker  solution 
would  be  sufficient  should  any  further  application  be  necessary. 

Perhaps  the  strongest  argument  in  favor  of  using  a  chemical  treat- 
ment of  this  kind  is  that  even  though  enough  copper  should  be  added 
to  a  reservoir  to  make  a  one-millionth  solution,  nothing  like  this 
amount  would  appear  in  the  water  distributed.  A  very  large  percent- 
age of  the  copper  is  combined  with  the  alga3  and  precipitated  in  other 
ways,  so  that  practically  none  would  remain  in  solution  after  the  first 
few  hours. a  Samples  of  water  taken  from  a  reservoir  treated  with 
sufficient  copper  sulphate  to  make  a  solution  of  one  to  one  million, 
failed  to  show  any  reaction  for  copper  after  twenty-four  hours, 
although  all  the  alga1  were  killed.  It  is  believed  that  the  process  used 
of  evaporating  down  the  original  quantity  and  testing  by  the  delicate 
potassium  ferro-cyanide  method  would  certainly  have  detected  copper 
had  it  been  present  in  the  proportion  of  one  to  fifty  million.  Other 
tests  were  made  by  different  chemists,  but  always  with  negative  results. 

In  addition  to  the  use  of  copper  sulphate  in  reservoirs  containing 
water  to  be  used  for  domestic  purposes,  there  are  possibilities  of  its 
application  in  treating  irrigation  reservoirs,  small  pleasure  lakes,  fish 
ponds,  oyster  beds,  etc.  Here  it  may  often  be  desirable  to  exceed  the 
strength  of  solution  that  would  represent  the  maximum  required  in  a 
municipal  water  supply.  This  would  be  done  not  only  to  kill  all  the 
algae,  but  to  destroy  or  drive  away  reptiles  and  other  pests,  leaving 
the  water  perfectly  clear  and  clean.  The  use  of  some  such  method 
for  the  destruction  of  mosquito  larva?  also  seems  worthy  of  attention. 
The  mere  removal  of  the  great  mass  of  algal  growths  in  stagnant  pools 
undoubtedly  reduces  the  number  of  larvre  by  destroying  this  source 

a  Adsorption,  according  to  True  and  Ogilvie  (Science,  N.  S.,  19:  421),  would  materi- 
ally reduce  the  quantity  of  copper  in  solution.  See  also  Bull.  No.  9,  Veg.  Phys.  and 
Path.,  U.  S.  Dept.  Agric. 


METHOD   OF   APPLYING   THE   COPPER   SULPHATE.  25 

of  their  food  and  depriving  them  of  protection  from  fish  and  other 
enemies.  This  is  probably  the  explanation  of  the  reported0  decrease 
in  the  number  of  mosquito  larva?  after  spraying  a  lily  pond  with 
Bordeaux  mixture,  although  it  is  possible  that  the  strength  of  the 
solution  r«^d  may  have  been  partly  responsible  for  their  death.  It 
is  belie vi  that  it  will  not  be  impracticable  to  use  the  amounts  of 
copper  si  ;hate  necessary  to  actually  destroy  such  larva?.  Certainly 
this  method  if  effective  offers  considerable  advantages  over  any  now  in 
use,  and  it  should  be  thoroughly  tested.  Cooperative  experiments 
are  now  under  way  with  the  Bureau  of  Entomology  to  determine  the 
strength  of  solution  necessary  to  kill  larvae  of  different  species  and  ages 
under  various  conditions. 

METHOD  OF  APPLYING  THE  COPPER  SULPHATE. 

The  method  of  introducing  the  copper  sulphate  into  a  water  supply  is 
extremely  simple.  Though  aiw  plan  will  suffice  which  distributes  the 
copper  thoroughly,  the  one  recommended  and  used  b}T  the  Department 
of  Agriculture  is  as  follows:  Place  the  required  number  of  pounds  of 
copper  sulphate  in  a  coarse  bag — gunny-sack  or  some  equally  loose 
mesh — and,  attaching  this  to  the  stern  of  a  rowboat  near  the  surface 
of  the  water,  row  slowly  back  and  forth  over  the  reservoir,  on  each 
trip  keeping  the  boat  within  10  to  20  feet  of  the  previous  path.  In 
this  manner  about  100  pounds  of  copper  sulphate  can  be  distrib- 
uted in  one  hour.  By  increasing  the  number  of  boats,  and,  in  the 
case  of  very  deep  reservoirs,  hanging  two  or  three  bags  to  each 
boat,  the  treatment  of  even  a  large  reservoir  may^  be  accomplished  in 
from  four  to  six  hours.  It  is  necessary,  of  course,  to  reduce  as  much 
as  possible  the  time  required  for  applying  the  copper,  so  that  for 
immense  supplies  with  a  capacity  of  several  billion  gallons  it  would 
probabl}T  be  desirable  to  use  a  launch,  carrying  long  projecting  spars 
to  which  could  be  attached  bags  each  containing  several  hundred 
pounds  of  copper  sulphate. 

In  waters  that  have  a  comparatively  high  percentage  of  organic 
acid  it  is  sometimes  advisable  to  add  a  sufficient  amount  of  lime  or 
some  alkali  hydrate  to  precipitate  the  copper.  The  necessity  for  this 
will  never  occur  in  a  limestone  region,  as  in  this  case  there  will  always 
be  enough  calcium  hydrate  or  carbonate  to  cause  the  desired  precipita- 
tion. The  precipitation  of  copper  does  not  mean  the  destruction  of 
its  toxicity,  for  experiments  conducted  in  this  laboratory  have  con- 
firmed Rumm's  *  results  that  the  insoluble  salts  of  copper,  such  as  the 
hydrate,  carbonate,  and  phosphate,  are  toxic  only  if  they  are  in  con- 
tact with  the  cell,  but  are  highly  toxic  in  that  case.  In  this  connection 
it  should  be  mentioned  that  Hedrick0  has  described  a  method  for  con- 

«Hedrick,  Gardening,  11:  295.  &  Rumm,  1.  c. 


26        METHOD    OF    DESTKOYIHG    ALGJE    IK    WATEK    SUPPLIES. 

trolling  the  growth  of  algal  scum  in  lily  ponds  by  the  use  of  Bordeaux 
mixture  which  seems  to  have  been  temporarily  effective.  However, 
the  impracticability  of  using  such  a  mixture  is  apparent  for  the 
destruction  of  microscopic  algae  distributed  through  a  reservoir  or  a 
lake  containing  millions  of  gallons. 

PRACTICAL  TESTS  OF  THE  METHOD. 

WATER-CRESS    BEDS. 

The  first  practical  test  of  the  treatment  of  water  for  the  purpose  of 
killing  out  extensive  growths  of  algae  was  made  in  the  fall  of  1901  near 
Ben,  Va.,  in  connection  with  the  cultivation  of  water  cress  for  market. 
Water  cress  is  grown  there,  as  well  as  in  other  parts  of  the  country, 
in  large  quantities  during  the  winter,  it  being  a  valuable  crop  at  that 
season  of  the  year.  The  cress  is  confined  in  beds  made  by  construct- 
ing dams  across  a  small  stream,  which  maintains  a  water  level  not  too 
high  for  the  growth  of  the  plants  and  yet  permits  flooding  when  there 
is  danger  of  a  freeze.  In  the  locality  where  the  experiments  were 
carried  on  the  water  was  obtained  from  a  thermal  spring  with  a  tem- 
perature the  year  around  of  about  70°  F.  Such  a  temperature  was 
particularly  favorable  to  the  development  of  Spirogyra  and  similar  fila- 
mentous algae,  so  that  when  the  cress  was  freshly  cut  they  frequently 
increased  to  such  an  extent  as  to  completely  smother  out  a  large  part 
of  the  young  and  tender  plants.  The  only  known  remedy  under  such 
conditions  was  to  rake  out  the  water  cress  and  algae  and  reset  the  entire 
bed.  This  was  an  expensive  method,  however,  besides  being  success- 
ful only  about  half  the  time.  Consequently,  it  was  very  desirable  to 
devise  some  means  of  preventing  the  growth  of  the  algae  without 
injuring  the  water  cress,  and  the  treatment  by  means  of  copper  sug- 
gested itself.  At  first  a  strong  solution  of  copper  sulphate  was  used, 
spraying  it  on  the  algal  covered  surface  of  the  beds,  but  this  only 
destroyed  the  few  filaments  with  which  the  copper  came  in  contact, 
the  large  mass  of  algae  being  practically  unaffected.  The  method  of 
applying  the  copper  by  means  of  dissolving  it  directly  in  the  beds  was 
next  tried,  and  the  success  of  the  treatment  was  almost  immediately 
evident.  In  this  case  the  amount  of  copper  added  was  about  equal  to 
a  strength  of  1  to  50,000,000  parts  of  water,  but  it  is  probable  that  by 
the  time  it  reached  most  of  the  Spirogyra  it  was  considerably 
weakened,  as  it  was  impossible  to  prevent  a  slight  current  of  fresh 
water  from  passing  through  the  beds  at  all  times. 

The  success  of  the  copper  treatment  for  eradicating  algae  from  cress 
beds  has  been  thoroughly  demonstrated,  and  there  is  no  reason  why 
growers  should  have  trouble  from  this  cause  in  the  future.  The  strength 
of  the  solution  used  for  killing  the  algae  is  so  very  much  weaker  than 
that  which  might  affect  the  cress  that  there  is  no  possible  danger  of 


PRACTICAL    TESTS    OF   THE   METHOD.  27 

injuring1  the  latter  if  the  solution  is  used  by  anyone  capable  of  observ- 
ing ordinary  care.  The  question  of  how  long  a  treatment  is  effective 
must,  of  course,  depend  upon  conditions,  but  it  is  believed  that  the 
application  of  the  proper  amount  of  copper  once  or  twice  a  year  will 
in  most  cases  be  sufficient  to  keep  down  any  algal  pest.  The  manager 
of  the  Virginia  Cress  Company  writes,  under  date  of  April  12,  1904: 

The  "moss"  has  given  me  no  trouble  at  all  this  winter.  In  fact  I  have  for  six 
months  only  had  to  resort  to  the  copper  sulphate  once.  *  *  *  All  the  conditions 
were  favorable  last  fall  and  early  winter  for  a  riot  of  "moss,"  but  it  did  not  appear 
at  all  until  just  a  few  days  ago,  and  then  yielded  to  treatment  much  more  readily 
than  it  did  when  I  first  began  to  use  the  copper. 

WATER   RESERVOIRS. 

The  successful  elimination  of  algae  from  the  cress  beds  of  the  South, 
under  conditions  which  were  particularly  favorable  to  the  growth  of 
these  pests,  made  it  desirable  that  experiments  be  inaugurated  calcu- 
lated to  demonstrate  the  possibility  of  ridding  water  reservoirs  of  the 
disagreeable  odors  and  tastes  caused  by  similar  organisms.  While  it 
was  realized  that  the  popular  prejudice  against  any  chemical  treat- 
ment of  drinking  water  was  strong,  it  was  believed  that  the  very  weak 
solution,  together  with  the  very  rapid  disappearance  of  the  salt  added, 
would  not  render  it  a  prohibitive  method  when  applied  under  the 
direction  of  the  proper  authorities.  It  was  also  found  that  consumers 
of  a  water  which  possessed  a  disgusting  odor  and  taste  were  not  so 
prejudiced  against  the  use  of  even  a  chemical  method  of  extermina- 
tion, provided  it  could  be  proved  that  no  bodily  harm  would  result. 

In  the  spring  of  1903  there  was  brought  to  the  notice  of  the  Depart- 
ment the  supply  of  a  water  company  in  Kentucky,  which  promised  to 
furnish  a  most  satisfactory  test.  Ever  since  the  construction  of  their 
reservoir  it  had  given  off  an  unpleasant  odor.  For  the  first  two  sea- 
sons this  was  supposed  to  be  due  to  decaying  vegetation,  but  later 
years  demonstrated  the  well-known  "pigpen"  odor  due  to  algae,  and 
this  increased  from  year  to  year  until  it  was  almost  unbearable. 

In  July,  1903,  when  the  trial  was  begun,  the  microscopical  examina- 
tion demonstrated  an  average  of— 

Anabsena per  cc. .  7, 400 

Clathrocystis do 1,100 

Eudorina % do 200 

There  were  about  25,000,000  gallons  of  water  in  the  reservoir  at  the 
time  of  the  experiment,  and  on  account  of  the  great  number  of  blue- 
green  algae  present  it  was  decided  to  apply  the  copper  at  a  strength  of 
1  to  4,000,000.  About  50  pounds  of  copper  sulphate  was  accordingly 
placed  in  a  coarse  sack  and  this,  attached  to  a  boat,  was  dragged  over 
the  surface  of  the  reservoir,  giving  especial  attention  to  the  region 
which  seemed  to  contain  the  greatest  number  of  Andbsena  filaments. 


28         METHOD    OF    DESTROYING    ALG^J    IN    WATER    SUPPLIES. 

The  decrease  in  the  number  of  organisms  as  the  result  of  this  treat- 
ment during  the  next  twenty-four  hours  was  very  decided.  In  two 
days  the  surface  was  clear  and  the  water  had  lost  its  blue-green  color, 
becoming  brown,  due  to  the  dead  organisms  held  in  suspension. 
There  was  a  slight  increase  in  odor  during  the  first  two  days  after 
treatment,  but  this  was  followed  by  a  gradual  subsidence  until  it  had 
entirely  disappeared,  not  to  appear  again  that  season.  The  following 
list  of  counts  made  from  surface  examinations  at  one  station  illus- 
trates what  went  on  throughout  the  reservoir,  and  shows  the  almost 
immediate  effect  of  a  1  to  4,000,000  solution  of  copper  sulphate  upon 
the  number  of  filaments  of  Anabdena  flos-aquaa.  The  treatment  was 
made  July  9. 

Filaments  per 
cubic  centimeter. 

July  6 3,  400 

July  10 54 

July  11 8 

July  13 0 

July  15 0 

July  20 0 

It  remains  to  be  seen  what  the  condition  will  be  during  the  coming 
summer,  but  it  is  believed  it  can  never  be  any  worse  than  at  the 
time  of  treatment,  and  it  is  reasonable  to  suppose  that  there  will  be 
considerably  fewer  organisms  this  }7ear  than  last.  Even  though  an 
annual  treatment  of  the  reservoir  prove  necessary,  involving  a  cost  of 
from  $25  to  $50,  the  alreadj^  great  improvement  in  the  quality  of  the 
water  will  certainly  make  it  justifiable. 

Other  experiments  of  a  similar  character  were  carried  on  in  different 
parts  of  the  country  with  reservoirs  of  a  capacity  of  from  10^000,000 
to  600,000,000  gallons.  While  the  results  were  all  favorable,  it  is 
deemed  best  not  to  publish  any  detailed  account  until  the  effect  of  the 
treatment  can  be  followed  through  another  season.  The  summer  of 
1903  was  cold  and  wet,  and  in  some  cases  the  decrease  in  the  number  of 
organisms  may  have  been  due  to  these  factors.  However,  the  several 
instances  of  the  very  sudden  and  rapid  disappearance  of  forms  which 
were  present  in  tremendous  quantity,  without  any  reappearance, 
indicated  that  the  treatment  was  most  effective.  Those  in  charge  of 
these  water  supplies  reported  that  they  were  well  satisfied  with  the 
result. 

EFFECT  OF  COPPER,  UPON  PATHOGENIC  BACTERIA. 

TYPHOID. 

The  value  of  copper  sulphate  as  an  agent  for  the  destruction  of 
algae  polluting  reservoirs  suggests  its  use  in  cases  where  the  organism 
is  pathogenic.  Since  this  salt  is  fatal  to  the  algal  growths,  it  seemed 


EFFECT  OF"  COPPER  UPON  PATHOGENIC  BACTERIA.      29 

probable  that  it  would  also  destroy  bacteria,  and  that  cholera  germs 
and  typhoid  germs  might  succumb  to  its  action. 

The  sterilization  of  public  water  supplies  by  chemical  means  has  so 
far  seemed  an  impossibility.  Nearly  every  known  substance  has  been 
tested,  but  the  high  concentrations  required  to  produce  the  desired 
effect,  the  extreme  toxicity  of  the  agents,  their  cost,  or  the  difficulty 
of  application,  have  eliminated  all  but  copper  sulphate  as  a  possibility 
for  the  present  purpose.  According  to  Semmer  and  Krajewski,a  a 
1  to  160  solution  of  this  salt  will  inhibit  action  in  infected  blood,  and 
septic  bacteria  can  be  destroyed  with  a  10  per  cent  solution.  Bolton  b 
says  that  1  to  500  is  toxic,  but  1  to  1,000  permits  the  growth  of  cholera; 
1  to  200  and  1  to  500,  respectively,  produce  the  same  results  with 
typhoid,  and  some  of  the  spore-bearing  forms  are  unaffected  at  2  per 
cent.  Green c  gives  2J  per  cent  as  the  amount  necessary  to  kill 
typhoid  in  two  to  twenty-four  hours,  and  finds  cholera  only  slightly 
less  sensitive.  Israel  and  Klingman,^  however,  find  that  almost 
infinitesimal  amounts  of  copper  in  colloidal  solution  are  fatal  to 
typhoid,  cholera,  and  Bacillus  coli.  There  is  considerable  literature 
upon  the  use  of  copper  sulphate  as  a  disinfectant  for  clothing,  bed- 
ding, cesspools,  etc.,  but  it  is  not  necessar3T  to  review  it  at  this  place. 
Sternberg^  found  that  its  germicide  power  was  decidedly  superior  to 
the  corresponding  salt  of  iron  and  zinc,  and  demonstrated  that  it 
destroyed  micrococci  from  the  pus  of  an  acute  abscess  in  the  propor- 
tion of  1  to  200.  He  says,  "This  agent  (ciipric  sulphate),  then,  is  a 
valuable  germicide  and  may  be  safely  recommended  for  the  disinfec- 
tion of  material  not  containing  spores.'' 

The  high  percentage  of  copper  sulphate  given  by  most  of  these 
authorities  seems  to  preclude  the  idea  of  its  practical  use  for  the  pur- 
pose desired.  It  should  be  remembered,  however,  that  these  investi- 
gators were  working  for  a  very  different  end,  namely,  to  find  concen- 
trations destructive  to  bacteria  in  the  presence  of  large  quantities  of 
albuminoid  and  fatty  matter.  Experiments  conducted  under  similar 
circumstances  have  confirmed  the  above  results,  but  the  conditions 
obtaining  in  public  water  supplies  are  widely  different.  Here  the 
amount  of  albuminoid  matter  is  so  small  that  the  death  point  of  the 
typhoid  or  cholera  organism  is  lowered  tremendously  and  very  dilute 
solutions  of  copper  are  shown  to  be  toxic.  The  tabulated  results  on 
the  succeeding  pages  demonstrate  this  fact. 

"Semmer  and  Krajewski,  Arch.  f.  exp.  Path.  u.  Pharmakol.,  14:  139. 
b Bolton,  Rep.  of  Com.  on  Disinfectants,  Am.  Pub.  Health  Assn.,  1888,  p.  153. 
c  Green,  Zeit.  fur  Hyg.,  13:  495. 
<*  Israel  and  Klingman,  Virchon's  Archiv.,  147:  293. 

^Sternberg,  Rep.  Com.  Disinfection,  Am.  Pub.  Health  Assn.,  1888,  p.  38.  See  also 
Infection  and  Immunity,  New  York  and  London,  1903. 


30        METHOD   OF    DESTROYING    ALG.E    IN    WATEK    SUPPLIES. 


•Effect  of  copper  sulphate  upon  Bacillus  typhi  at  different  temperatures. « 
[Determination  made  in  tubes  of  bouillon.    +  indicates  growth  after  48  hours'  incubation;  -  indi- 
cates no  growth.] 


Duration  of  exposure  to  action  of  copper 
sulphate. 

I 

Tempera- 
ture. 

Check. 

1  part  cop- 
per sul- 
phate to 
100,000 
parts  of 
water. 

1  part  cop- 
per sul- 
phate to 
200,000 
parts  of 
water. 

1  part  cop- 
per sul- 
phate to 
500,000 
parts  of 
water. 

f           38 

+ 

+ 

+ 

28 

+ 

+ 

+ 

+ 

23.5 

_j_ 

_j. 

-1- 

-j. 

14 

+ 

+ 

+ 

+ 

4 

+ 

+ 

+ 

+ 

38 

+ 

- 

+ 

+ 

28 

+ 

- 

+ 

+ 

4  hours                                                        .... 

23.5 

.j. 

(?) 

_l_ 

.(- 

14 

+ 

+ 

+ 

+ 

4 

+ 

+ 

+ 

+ 

38 

+ 

- 

- 

+ 

28 

+ 

- 

-f 

+ 

6  hours                          

23.5 

_^_ 

._ 

_l_ 

+ 

14 

+ 

+ 

+ 

+ 

4 

+ 

-f 

+ 

+ 

38 

+ 

- 

- 

+ 

28 

+ 

- 

+ 

+ 

12  hours 

23.5 

• 

_ 

_!_ 

_l_ 

14 

+ 

— 

+ 

+ 

4 

+ 

(?) 

+ 

+ 

a  Experiment  conducted  in  test  tubes,  each  containing  5  cc.  of  sterilized  water,  portions  of  which 
had  been  previously  treated  with  the  desired  amounts  of  copper  sulphate.  All  tubes  inoculated  with 
a  3  mm.  loop  of  a  24-hour  culture  of  B.  typhi. 

Effect  of  copper  sulphate  upon  Bacillus  typhi  cultures  of  various  ages.a 

[Determination  made  in  tubes  of  bouillon.     +  indicates  growth  after  48  hours'  incubation;  —  indi- 
cates no  growth.] 


Duration  of  exposure  to  ac- 
tion of  solution  of  1  part 
copper  sulphate  to  100,000 
parts  of  water. 

Culture  36 
hours 
old. 

Culture  24 
hours 
old. 

Culture  18 
hours 
old. 

Culture  12 
hours 
old. 

Culture  6 
hours 
old. 

Culture  3 
hours 
old. 

+ 

+ 

-t- 

-j- 

6  hours 

(?) 

__ 

9  hours  

_ 

_ 

«  Experiment  conducted  in  test  tubes  each  con  taining  5  cc.  of  sterilized  water,  portions  of  which  had 
been  previously  treated  with  the  desired  amount  of  copper  sulphate.  All  tubes  inoculated  with  a 
3  mm.  loop  of  a  culture  of  B.  tyjthi  of  the  proper  age. 

Effect  of  copper  sulphate  on  Bacillus  typhi  at  different  temperatures.a 
[Determination  made  in  Petri  dishes.] 


Duration  of  exposure  to  action  of 
copper  sulphate. 

Tempera- 
ture. 

Check. 

One  part 
copper  sul- 
phate to 
100,000  parts 
of  water. 

One  part 
copper  sul- 
phate to 
200,000  parts 
of  water. 

One  part 
copper  sul- 
phate to 
500,000  parts 
of  water. 

2  hours 

0  C. 
5 

Colonies. 
720 

Colonies. 
315 

Colonies. 
1  440 

Colonies. 
894 

2  hours  

38 

1  260 

o 

312 

917 

5  hours  . 

5 

155 

115 

495 

278 

5  hours 

38 

37 

O 

g 

21 

a  Experiment  conducted  in  test  tubes  each  containing  5  co.  of  sterilized  water,  portions  of  which 
had  been  previously  treated  with  the  proper  amounts  of  copper  sulphate.  All  tubes  inoculated  with 
a  3  mm.  loop  of  an  18-hour  culture  of  B.  typhi. 


EFFECT  OF  COPPER  UPON  PATHOGENIC  BACTERIA. 


31 


Effect  of  copper  sulphate  upon  Bacillus  typhi  at  room  temperature.** 
[Determination  made  in  Petri  dishes.] 


Duration  of  exposure 
to  action  of  copper 
sulphate. 

Check. 

One  part  copper  sulphate  to— 

100,000  parts 
water. 

200,000  parts 
water. 

500,000  parts 
water. 

1,000,000  parts 
water. 

5,000,000  parts 
water. 

5  hour  

1,650 
1,836 
1,566 
1,485 
999 
1,134 
1,080 
783 
270 
297 

Colonies. 
5,481 
918 
1,026 
864 
243 
180 
156 
108 
0 
0 

Colonies. 
2,376 
2,106 
1,242 
1,296 
1,620 
1,161 
783 
972 
72 
14 

Colonies. 
2,754 
2,403 
1,323 
2,835 
1,485 
1,620 
918 
1,998 
405 
42 

Colonies. 
2,646 
1,377 
2,673 
2,430 
2,727 
1,782 
2,079 
1,836 
324 
243 

Colonies. 
3,645 
1,756 
2,808 
3,024 
2,106 
756 
1,242 
1,458 
459 
405 

1  hour 

U  hours  

2  hours  

2J  hours 

3  hours  

3f  hours 

4  hours  

8  hours 

12  hours                

«  Experiment  conducted  in  test  tubes  each  containing  5  cc.  of  sterilized  water,  portions  of  which 
had  been  previously  treated  with  the  desired  amounts  of  copper  sulphate.  All  tubes  inoculated  with 
a  3  mm.  loop  of  an  18-hour  culture  of  B.  typhi. 

Effect  of  copper  sulphate  upon  Bacillus  typhi  at  room  temperature." 
[Determination  made  in  Petri  dishes.] 


Duration  of  expo- 
sure to  action  of 
copper  sulphate. 

No.  1.  Check. 

No.  2.  One  part 
copper  sul- 
phate to 
200,000    parts 
water. 

No.  3.  One  part 
copper  sul- 
phate to 
100,000  parts 
water. 

No.  4.  One  part 
copper  sulphate 
to  50,000  parts 
water. 

No.  5.  One  part 
copper  sul- 
phate to 
100,000  parts 
water. 

Colonies. 

Colonies. 

Colonies. 

Colonies. 

Colonies. 

ft 

4 

3 

s 

Q 

u 

•F 

& 

li 
I 

- 

*o 
-3 

§ 

c> 

1 

f* 

£, 

5^- 

3 

"o 

~. 

0 

f 

r 

>> 
It 

"o 
g 

« 

If 

!•* 

T.       • 

.=  .= 

—  z. 

i 

as 

'O 

1 

C) 

1 
s* 

0  hour  

f      144 

\      792 
f  14,  634 
116,212 
f      954 
5H 
(24,300 
119,400 
J20,484 
|19,  674 
f  6,156 
121,600 

4 
2 
2 
0 
0 
3 
2 
0 
0 
0 
0 
0 

5 
4 
7 
0 
2 
31 
8 
0 
0 
0 
33 
0 

108 
90 
11 
126 
0 
0 
0 
0 
0 
0 
0 
0 

2 
1 
0 
0 
t) 
0 

1 
1 

0 
0 
0 

0 

7 
4 
5 
2 
1 
0 
1 
5 
2 
0 
0 
0 

3 
198 
72 
6 
0 
0 
0 
0 
0 
0 
0 
0 

1 
.  1 
3 
0 
0 
0 
0 
0 
0 
0 
0 
0 

4 
5 
4 
0 
0 
0 

1 

0 

1 

3 
0 
0 

3,672 
5,742 
0 
4 
0 
0 
0 
0 
0 
0 
0 
0 

0 

1 

0 
0 
0 
0 
0 
0 
0 

6 

0 
0 

0 

1 

0 

1 

0 
3 
0 
3 
0 
2 
0 
0 

234 
306 
6 
4 
0 
0 
0 
0 
0 
0 
0 
0 

0 
0 
0 

1 

2 
0 
0 

1 

0 

1 

0 
0 

5 
0 
.      0 
0 
0 
0 
0 

1 

0 
0 
0 
0 

3  hours 

4  hours  

6  hours  

8  hours  ...     . 

12  hours  

a  Experiment  conducted  in  12-liter  aquaria.  No.  1  was  untreated;  copper  sulphate  was  added  to 
Nos.  2,  3,  4,  and  5.  Three  cubic  centimeters  of  a  mixture  of  cultures  of  B.  typhi  were  added  to  each 
jar  18  hours  before  treating.  All  small  nonliquifying  colonies  counted  as  typnoid. 

28480— No.  64—04 3 


32 


METHOD    OF    DESTROYING    ALG^E    IN    WATER    SUPPLIES. 


Effect  of  copper  sulphate  upon  Bacillus  typhi  at  low  temperature.0 
[Determination  made  in  Petri  dishes.] 


Duration  of  exposure  to  action  of  copper  sulphate. 

Tempera- 
ture. 

Check. 

One  part 
copper  to 
100,000 
parts  water. 

3  hours    -  

0  C. 
5 

Colonies. 

2,187 

Colonies. 
1,944 

6  hours 

5 

2  646 

881 

9  hours                                 

5 

1,026 

702 

12  hours 

5 

351 

98 

24  hours 

5 

37 

o 

a  Experiment  conducted  in  test  tubes  each  containing  5  cc.  of  sterilized  water,  part  of  which  had 
been  previously  treated  with  the  desired  amount  of  copper  sulphate.  All  tubes  inoculated  with  a 
3  mm.  loop  of  a  culture  of  B.  typhi  of  the  proper  age. 

Effect  of  copper  sulphate  upon  Bacillus  coli  cultures  of  various  ages. a 

[Determination  made  in  tubes  of  bouillon.     +  indicates  growth  after  48  hours'  incubation;  —  indi- 
cates no  growth.] 


Duration  of  exposure  to 
action  of  solution  of  1  part 
copper  sulphate  to  100,000 
parts  water. 

Culture  36 
hours  old. 

Culture  24 
hours  old. 

Culture  18 
hours  old. 

Culture  12 
hours  old. 

Culture  6 
hours  old. 

Culture  3 
hours  old. 

3  hours  

+ 

+ 

+ 

+ 

+ 

6  hours 

_• 

+ 

9  hours           

+ 

a  Experiment  conducted  in  test  tubes  each  containing  5  cc.  of  sterilized  water,  part  of  which  had 
been  previously  treated  with  the  desired  amount  of  copper  sulphate.  All  tubes  inoculated  with  a 
3  mm.  loop  of  a  culture  of  B.  coli  of  the  proper  age. 

Effect  of  copper  sulphate  upon  Bacillus  coli  at  different  temperatures.a 

[Determination  made  in  tubes  of  bouillon.     +  indicates  growth  after  48  hours'  incubation;  —  indi- 
cates no  growth.] 


Duration  of  exposure  to  action  of 
copper  sulphate. 

Tempera- 
ture. 

Check. 

One  part  copper  sulphate  to  — 

100,000  parts 
water. 

200,000  parts 
water. 

500,000  parts 
water. 

0  C. 

38 

+ 

+ 

+ 

+ 

28 

+ 

+ 

+ 

+ 

2  hours  

23.5 

+ 

+ 

+ 

+ 

14 

+ 

+ 

+ 

+ 

4 

+ 

+ 

+ 

+ 

38 

+ 

- 

+ 

+ 

28 

+ 

+ 

+ 

+ 

4  hours 

23.5 

_(- 

-{. 

-j- 

+ 

* 

14 

+ 

+ 

+ 

4 

+ 

+ 

+ 

+ 

38 

+ 

- 

+ 

+ 

28 

+ 

+ 

+ 

+ 

6  hours  

23.5 

_l_ 

+ 

+ 

-f- 

•  14 

+ 

+ 

+ 

+ 

4 

+ 

+ 

+ 

+ 

a  Experiment  conducted  in  test  tubes  each  containing  5  cc.  sterilized  water,  portions  of  which  had 
been  previously  treated  with  the  desired  amounts  of  copper  sulphate.  All  tubes  inoculated  with  a 
3-mm.  loop  of  a  24-hour  culture  of  B.  coli. 


EFFECT  OF  COPPER  UPON  PATHOGENIC  BACTERIA. 


33 


Effect  of  copper  sulphate  upon  Bacillus  coli  at  room  temperature.  a 
[Determination  made  in  Petri  dishes.] 


Duration   of   expo- 
sure to  action  of 
copper  sulphate. 

Check. 

1  part  copper  sulphate  to— 

100,000  parts 
of  water. 

200,000  parts 
of  water. 

500,000  parts 
of  water. 

1,000,000  parts 
of  water. 

5,000,000  parts 
of  water. 

i  hour  

Colonies. 
3,888 
3,456 
2,592 
2,079 
3,969 
2,457 
1,666 
1,323 
1,107 
297 

Colonies. 
5,697 
2,295 
2,565 
1,971 
2,835 
1,701 
1,404 
675 
96 
5 

Colonies. 
4,455 
1,755 
1,755 
3,429 
2,295 
1,242 
2,295 
1,593 
459 
43 

Colonies. 
8,937 
2,700 
2,403 
1,890 
3,456 
3,834 
1,431 
2,403 
1,026 
366 

Colonies. 
5,490 
3,483 
1,377 
3,267 
2,214 
2,106 
2,025 
1,674 
513 
513 

Colonies. 
6,426 
2,160 
1,873 
3,942 
2,349 
3,078 
3,240 
1,836 
1,728 
891 

1  hour 

H  hours  

2  hours 

2£  hours           

3  hours 

3£  hours           

4  hours 

8  hours             .     . 

12  hours  

«  Experiment  conducted  in  test  tubes,  each  containing  5  cc.  of  sterilized  water,  portions  of  which 
had  been  previously  treated  with  the  desired  amounts  of  copper  sulphate.  All  tubes  inoculated  with 
a  3  mm.  loop  of  an  18-hour  culture  of  B.  coli. 

Effect  of  copper  itulphale  upon  Bacillus  coli  at  low  temperature.a 
[Determination  made  in  Petri  dishes.] 


Duration  of  exposure  to  action  of  copper  sulphate. 

Temper- 
ature. 

Check. 

1  part  cop- 
per to  100,- 
000  parts 
water. 

3  hours 

°a 

5 

Colonies. 
2  700 

Colonies. 
2  673 

6  hours  . 

5 

3  591 

1  620 

9  hours  . 

5 

2,403 

1,215 

12  hours 

2  106 

1  431- 

a  Experiment  conducted  in  test  tubes  each  containing  5  cc.  of  sterilized  water,  part  of  which  had 
been  previously  treated  with  the  desired  amount  of  copper  sulphate.  All  tubes  inoculated  with  a 
3  mm.  loop  of  a  culture  of  B.  coli  of  the  proper  age. 

Effect  oj  copper  sulphate  upon  paracolon  cultures  of  various  ages. a 

[Determination  made  in  tubes  of  bouillon.     +  indicates  growth  after  48  hours'  incubation;  —indi- 
cates no  growth.] 


Duration  of  exposure  to  ac- 
tion of  solution  of  1  part 
copper  sulphate  to  100,000 
parts  of  water. 

Culture  36 
hours  old. 

Culture  24 
hours  old. 

Culture  18 
hours  old. 

Culture  12 
hours  old. 

Culture  6 
hours  old. 

Culture  3 
hours  old. 

3  hours 

? 

6  hours  

? 

9  hours 

a  Experiment  conducted  in  test  tubes  each  containing  5  cc.  of  sterilized  water,  part  of  which  had 
been  previously  treated  with  the  desired  amount  of  copper  sulphate.  All  tubes  inoculated  with  a 
3  mm.  loop  of  a  culture  of  paracolon  of  the  proper  age. 

These  tables  show  that  Bacillus  typhi  is  more  sensitive  to  copper 
sulphate  than  is  coli,  that  the  para  group  are  about  equally  sensitive, 
and  that  temperature  has  a  very  important  bearing  on  the  toxicity  of 


84         METHOD    OF    DESTROYING    ALGJE    IN    WATER    SUPPLIES. 

the  copper  in  solution.  At  room  temperature,  which  is  near  the  tem- 
perature of  a  reservoir  in  summer,  a  dilution  of  1  to  100,000  is  fatal  to 
typli i  in  three  to  five  hours;  at  5°  it  requires  twenty-four  hours  for 
complete  destruction. 

The  results  obtained  were  checked  in  three  ways: 

(1)  Five  cubic  centimeters  of  each  of   the  solutions  to  be  tested, 
made   up  with  filtered  hydrant  water  and  check  tubes  of  the  same 
water,  were  sterilized  in  test  tubes.     To  each  of  these -was  transferred 
one  3-mm.  loop  of  a  bouillon  culture  of  the  bacillus.     After  the  proper 
exposure,  a  3-mm.  loop  of  the  inoculated  water  from  each  tube  was 
transferred  to  a  sterile  bouillon  tube  with  a  corresponding  number. 
These  bouillon  tubes  were  then  incubated  forty-six  hours  at  38°,  the 
time  and  concentration  of  the  agent  required  to  prevent  growth  being 
noted. 

(2)  Instead  of  transferring  to  bouillon  tubes  from  the  inoculated 
water,  the  transfer  was  made  to  gelatine  tubes,  and  plates  were  poured 
in  10-cm.  Petri  dishes,  thus  making  it  possible  to  estimate  the  reduc- 
tion in  the  number  of  bacteria  in  concentrations  not  sufficient  to  pre- 
vent growth. 

(3)  Five  12-liter  aquaria,  two  of  which  contained  a  high  percentage 
of  organic  matter,  also  a  large  quantity  of  algse  and  other  aquatic 
plants,  were  inoculated,  each  wdth  3  cubic  centimeters  of  cultures  of 
Bacillus  typhi  of  different  ages,  and  allowed  to  stand  eighteen  hours, 
and  two  poured  plates  were  made  from  each  aquarium,  the  3-rnm.  loop 
being  used  in  all  cases.     To  these  aquaria  were  then  added  a  1  per 
cent  solution  of  copper  sulphate  in  sufficient  quantity  to  produce  the 
desired  concentration.     After  the  proper  time  had  elapsed,  another 
series  of  plates  was  made,  this  being  repeated  every  two  hours  for  a 
period  of  twelve  hours. 

The  tests  were  made  upon  four  distinct  cultures  of  Bacillus  typhi, 
designated  respectively  Wasserman,  Stokes,  Say,  and  Longcope,  and 
except  in  the  case  of  the  aquaria  series,  upon  Bacillus  coll  and  some 
of  the  para  forms.  These  organisms  were  obtained  from  the  labora- 
tory of  H.  K.  Mulford  &  Co. 

ASIATIC    CHOLERA. 

The  method  of  procedure  in  determining  the  toxic  concentration  for 
Microspira  comma  (Spirillum  choleras)  was  identical  to  that  .employed 
in  the  case  of  Bacillus  typhi.  The  tables  on  the  next  page  show  that 
the  toxic  limits  of  these  two  pathogenic  organisms  are  very  similar  and 
that  Microspira  comma  is  slightly  more  sensitive  to  copper  sulphate 
than  is  Bacillus  typhi.  To  destroy  the  cholera  germ  requires  about 
three  hours  in  a  1  to  100,COO  solution  at  a  temperature  above  20°.  A 
longer  exposure  or  a  higher  concentration  is  necessary  to  produce  this 
result  at  lower  temperatures. 


EFFECT    OF    COPPER   UPON    PATHOGENIC    BACTERIA. 


35 


Effect  of  copper  sulphate  upon  Microspira  comma  at  different  temperatures.  <* 

v 

[Determination  made  in  Petri  dishes.] 


Duration  of  exposure  to  action  of 
copper  sulphate. 

Tempera- 
ture. 

Check. 

One  part  copper  sulphate  to— 

100,000  parts 
water. 

200,000  parts    500,000  parts 
water.              water. 

2  hours  

°C. 
5 
15 
26 
30.5 
5 
15 
26.5 
30.5 
5 
15 
26.5 
30.5 

Colonies. 
1,866 
2,500 
3,500 
4,556 
1,533 
1,033 
1,033 
1,466 
2,000 
3,033 
3,600 
1,066 

Colonies. 
1,400 
533 
3 
7 
133 
21 
.0 
0 
32 
9 
0 
0 

Colonies. 
566 
1,100 
100 
66 
13 
72 
6 
0 
9 
20 
166 
0 

Colonies. 
3,366 
1,000 
733 
1,433 
766 
95 
11 
12 
700 
84 
533 
90 

4  hours  

6  hours 

a  Experiments  conducted  in  test  tubes,  each  containing  5  cc.  of  sterilized  water,  portions  of  which 
had  been  previously  treated  with  the  desired  amounts  of  copper  sulphate.  All  tubes  inoculated 
with  a  3  mm.  loop  of  a  14-hour  culture  of  Jf.  comma. 

Effect  of  copper  sulphate  upon  Microspira  comma  at  different  temperatures.*1 

[Determinations  made  in  bullion  tubes.     +  indicates  growth  after  48  hours'  incubation;  —  indicates 

no  growth.] 


Duration  of  exposure  to  action  of 
copper  sulphate. 

Tempera- 
ture. 

Check. 

1  part  of  copper  sulphate  to  — 

100,000  parts    200,000  parts 
water.              water. 

500,000  parts 
water. 

2  hours  

°C. 

\           1? 
1            24.4 

[            30.5 

I            1? 
24.4 

[           30.5 

f            1? 
24.4 

I           30.5 

+ 
+ 
-f 
+ 
4- 
+ 
+ 
+ 
+ 

+ 

+ 

+ 

+ 
+ 

+ 
+ 

+ 
+ 

+ 
+ 
+ 
-f 
+ 
+ 
+ 

4  hours  

6  hours 

a  Experiment  conducted  in  test  tubes  each  containing  5  cc.  of  sterilized  water,  part  of  which  had 
been  previously  treated  with  the  desired  amount  of  copper  sulphate.  All  tubes  inoculated  with  a 
3  mm.  loop  of  a  16-hour  culture  of  M.  comma. 

It  will  be  seen  that  the  concentration  of  copper  required  is  consid- 
erably greater  than  the  maximum  necessary  for  the  destruction  of 
algae,  and  would,  of  course,  be  injurious  to  the  aquatic  animals  nor- 
mally present  in  a  reservoir  if  it  were  allowed  to  act  for  any  great 
length  of  time.  Experiments  in  this  laboratory  have  demonstrated, 
however,  that  the  time  necessary  to  remove  Bacillus  typhi  is  from 
three  to  four  hours  in  summer,  twent}'-four  hours  in  the  coldest 
weather,  and  that  under  such  conditions  the  solution  does  not  injure  fish 
and  frogs  or  the  common  aquatic  plants  such  as  Elodea,  Myriophyllum, 
and  Lemna.  To  remove  the  copper  at  the  desired  time  the  method 


36         METHOD    OF    DESTROYING    ALG^E    IN    WATER    SUPPLIES. 

suggested  in  the  preceding  section  in  the  case  of  acid  and  soft  waters 
may  be  employed — that  is,  precipitate  the  copper  by  some  soluble 
hydroxide  or  carbonate.  This  somewhat  complicates  the  treatment, 
as  it  will  be  necessary  to  determine  from  the  character  of  the  water 
the  amount  of  copper  necessary  to  produce  a  solution  of  1  to  100,000, 
as  well  as  to  estimate  how  much  of  the  hydroxide  or  carbonate  should 
be  added.  That  such  work  be  conducted  under  the  constant  and  direct 
supervision  of  competent  authorities  is  even  more  important  than  when 
treating  for  algal  contamination. 

COMPARISON  OF  EFFECT  OF  OTHER  DISINFECTANTS. 

A  comparison  of  the  efl'ect  of  copper  sulphate  with  certain  other 
substances  commonly  used  as  disinfectants  is  instructive,  and  gives 
some  idea  of  the  great  toxicity  of  this  metal.  Mercuric  chloride  (cor- 
rosive sublimate)  is  slightly  more  fatal  to  typhoid  and  cholera  than 
copper  sulphate  acting  at  a  lower  temperature  and  in  a  shorter  length 
of  time.  Carbolic  acid,  one  hundred  times  as  strong  as  the  dilution 
found  to  be  effective  for  copper  sulphate,  and  acting  eight  times  as 
long,  failed  to  kill.  The  same  is  true  of  formalin  used  between  fifteen 
and  twenty  times  the  strength  of  a  1  to  100,000  solution.  Using  one 
thousand  times  the  amount  of  citric  acid  that  would  be  used  of  copper 
sulphate  produces  death.  Thymol  is  effective  in  six  hours  when  used 
in  a  solution  of  1  to  5,000,  and  naphthalene  is  five  times  weaker. 

COLLOIDAL,   SOLUTIONS. 

The  preceding  experiments  have  dealt  with  copper  in  solution  as  the 
salt, of  some  acid.  The  effect  upon  water  of  metallic  copper  surfaces, 
producing  the  so-called  colloidal  solution  of  copper,  deserves  especial 
mention.  As  Niigeli,  Galeotti,  and  Israel  and  Klingman  have  abun- 
dantly demonstrated,  the  slight  amounts  of  copper  thus  brought  into 
solution  are  highly  toxic  to  many  forms  of  algae  and  bacteria. 

The  experiments  carried  on  in  this  laboratory^  show  that  it  is 
undoubtedly  possible  to  exterminate  Uroglena  and  some  forms  of 
Spirogyra  by  suspending  in  the  water  copper  foil  sufficient  to  give 
an  area  of  about  1  sq.  cm.  to  each  100  cc.  of  water.  This  would  not 
be  a  practicable  method  of  treating  a  reservoir,  but  it  suggests  the 
possibility  of  sheet  copper  being  used  as  a  preventive  of  pollution. 
By  suspending  large  sheets  of  this  metal  at  the  intake  of  a  reservoir, 
it  is  probable  that  conditions  would  be  rendered  sufficiently  antago- 
nistic to  algal  growth  to  maintain  the  sterility  of  a  reservoir  after 
it  had  once  been  thoroughly  cleansed  of  polluting  forms.  It  would, 
of  course,  be  necessary  to  keep  such  copper  sheets  clean  in  order  to 
prevent  a  reduction  of  the  toxic  action  due  to  the  formation  of  an 
insoluble  or  slimy  coating  on  its  surface.  It  is  possible  that  some 


COLLOIDAL    SOLUTIONS. 


37 


electrical  method  may  be  perfected  for  rapidly  obtaining  a  strong 
colloidal  solution,  which  frill  furnish  a  more  convenient  means  of 
application  than  that  of  the  crude  salt. 

In  regard  to  the  bacteria  causing  cholera  and  typhoid,  the  impor- 
tance of  the  specific  toxic  effect  of  colloidal  copper  is  probably  much 
greater  than  with  algae.  The  following  tables  show  the  proportions 
of  the  area  of  copper  to  the  quantity  of  water  and  to  the  time  and  the 
temperature  necessary  to  produce  the  complete  sterilization  of  water 
containing  these  pathogenic  germs: 

Effect  upon  Bacillus  typhi  of  exposure  to  colloidal  solution  of  copper  at  room  temperature.0 

[Determination  made  in  tubes  of  bouillon.     -f  indicates  growth  after  48  hours'  inoculation;  —  indi- 
cates no  growth.] 


Duration  of  exposure  to  action  of  copper. 

Check. 

15  sq.  mm. 
copper  foil 
in  10  cc.  of 
water. 

lOOsq.mm. 
copper  foil 
inlOcc.  of 
water. 

225sq.mm. 
copper  foil 
in  10  cc.  of 
water. 

10  hours.        

+ 

+ 

-j- 

+ 

16  hours 

-)- 

+ 

-)_ 

20  hours 

+ 

-f- 

50  hours  

+ 

-f 

a  Experiment  conducted  in  test  tubes  containing  10  cc.  each  of  sterilized  water.  The  copper  foil 
was  sterilized  and  added  immediately  before  inoculating  the  tubes  with  the  usual  3  mm.  loop  of  a 
24-hour  culture  of  B.  typhi.  This  experiment  was  duplicated  with  three  separate  strains  of  typhoid 
with  identical  results. 

Effect  upon  Bacillus  typhi  of  exposure  to  colloidal  solution  of  copper  at  room  temperature.0 
[Determination  made  in  Petri  dishes.] 


Duration  of  exposure  to  action  of  copper. 

Check. 

1  sq.  cm. 
copper  foil 
to  5  cc.  of 
water. 

4  sq.  cm. 
copper  foil 
to  5  cc.  of 
water. 

i  hour 

Colonies. 
1  650 

Colonies. 
2  241 

Colonies. 
2  025 

1  hour  

1  836 

1  944 

2  349 

Hhours  

1  566 

1  620 

1  188 

2  hours 

1  485 

1  674 

1  188 

2i  hours  

999 

675 

1  053 

3  hours 

1  134 

972 

918 

3£  hours  

1  080 

1  242 

621 

4  hours 

783 

837 

360 

8  hours  

270 

216 

o 

12  hours 

097 

24 

o 

« Experiment  conducted  in  test  tubes,  each  containing  5  cc.  of  sterilized  water.  The  copper  foil 
was  sterilized,  and  added  immediately  before  inoculating  the  tubes  with  the  usual  3  mm.  loop  of  a 
24-hour  culture  of  B.  typhi. 


38 


METHOD    OF    DESTROYING    ALG^E    IN-  WATER    SUPPLIES. 


Effect  upon  Bacillus  coli  of  exposure  to  colloidal  solution  of  copper  at  room  temperature.® 

[Determination  made  in  tubes  of  bouillon,    -f  indicates  growth  after 48  hours'  inoculation;  —  indicates 

no  growth.] 


Duration  of  exposure  to  action  of  copper. 

Check. 

15  sq.  nun- 
copper  foil 
in  10  cc.  of 
water. 

100  sq.  mm. 
copper  foil 
in  10  cc.  of 
water. 

225  sq.  mm. 
copper  foil 
in  10  cc.  of 
water. 

10  hours 

-)- 

-j- 

-)- 

_l- 

16  hours 

+ 

+ 

+ 

20  hours            .     .          

+ 

+ 

+ 

50  hours 

+ 

4. 

+ 

a  Experiment  conducted  in  test  tubes  containing  10  cc.  each  of  sterilized  water.  The  copper  foil  was 
sterilized  and  added  immediately  before  inoculating  the  tubes  with  the  usual  3  mm.  loop  of  a  24-hour 
culture  of  B.  coli. 

Effect  upon  Bacillus  coli  of  exposure  to  colloidal  solution  of  copper  at  room  temperature. a 
[Determination  made  in  Petri  dishes.] 


Duration  of  exposure  to  action  of  copper. 

Check. 

1  sq.  cm. 
copper  foil 
to  5  cc.  of 
water. 

4  sq.  cm. 
copper  foil 
to  5  cc.  of 
water. 

£  hour          '.  

Colonies. 
3,888 

Colonies. 
2,  241 

Colonies. 
3,024 

1  hour 

3,456 

1,971 

2,025 

li  hours                                                                                              

2,592 

1,512 

2,754 

2  hours      

2,079 

1,188 

1,846 

2*  hour-! 

3,969 

1,242 

999 

3  hours                                                                                                

2,457 

1,242 

1,593 

85  hours  

1,566 

1,  026 

2,727 

4  hours 

1,323 

1,323 

810 

8  hours                                       

1,107 

702 

69 

12  hours  

297 

348 

0 

a  Experiment  conducted  in  test  tubes,  each  containing  5  cc.  of  sterilized  water.  The  copper  foil 
was  sterilized  and  added  immediately  before  inoculating  the  tubes  with  the  usual  3-mm.  loop  of  a 
24-hour  culture  of  B.  coli. 


Effect  upon  par acolon  of  exposure  to  collodial  solution  of  copper  at  room  temperature. a 

[Determination  made  in  tubes  of  bouillon.     +  indicates  growth  after  48  hours'  inoculation;  —  indi- 
cates no  growth.] 


Duration  of  exposure  to  action  of  copper. 

Check. 

15  sq.  mm. 
copper  foil 
in  10  cc.  of 
water. 

100  sq.  mm. 
copper  foil 
in  10  cc.  of 
water. 

225  sq.  mm. 
copper  foil 
in  10  cc.  of 
water. 

5  hours 

+ 

-)- 

+ 

10  hours 

+ 

+ 

+ 

16  hours  

+ 

+ 

+ 

_ 

20  hours 

-f 

-j- 

50  hours  

+ 

+ 

a  Experiment  conducted  in  test  tubes  containing  10  cc.  each  of  sterilized  water.  The  copper  foil  was 
sterilized  and  added  immediately  before  inoculating  the  tubes  with  the  usual  3mm.  loop  of  a  24-hour 
culture  ot  paracolon.  This  experiment  was  duplicated  upon  another  form  of  paracolon  with  exactly 
the  same  results.  - 


COLLOIDAL    SOLUTIONS. 


Effect  upon  paratyphoid  of  exposure  to  colloidal  solution  of  copper  at  room  temperature. « 

[Determination  made  in  tubes  of  bouillon.     +  indicates  growth  after  48  hours'  inoculation;  —indi- 
cates no  growth.] 


Duration  of  exposure  to  action  of  copper. 

Check. 

15  sq.  mm. 
copper  toil 
in  10  cc.  of 
water. 

100  sq.  mm. 
copper  foil 
in  10  cc.  of 
water. 

225  sq.  mm. 
copper  foil 
in  10  cc.  of 
water. 

10  hours                                                                            .... 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

20  hours                                                                  

+ 

+ 

+ 

-f 

a  Experiment  conducted  in  test  tubes  containing  10  cc.  each  of  sterilized  water.  The  copper  foil 
was  sterilized  and  added  immediately  before  inoculating  the  tubes  with  the  usual  3  mm.  loop  of  a 
24-hour  culture  of  paratyphoid. 

Effect  upon  Microspira  comma  of  colloidal  solution  of  copper  at  various  temperatures. a 
[Determination  made  in  Petri  dishes.] 


Duration  of  exposure  to  action  of  copper. 

Tempera- 
ture. 

Check. 

|  sq.  cm. 
copper  foil 
to5cc. 
water. 

2  sq.  cm. 
copper  foil 
to  5  cc. 
water. 

0  C. 

Colonies. 

Colonies. 

Colonies. 

5 

1,866 

833 

2,500 

2  hours 

15 

2,500 

733 

2,433 

26.5 

3,500 

4,600 

333 

30.5 

4,556 

1,666 

533 

5 

1,533 

52 

29 

4  hours 

15 

1,033 

633 

366 

26.5 

1,033 

200 

0 

30.5 

1,466 

8 

30 

5 

2,000 

700 

10 

6  hours..  

15 

3,033 

45 

17 

26.5 

3,600 

300 

0 

30.5 

1,066 

4 

8 

«  Experiments  conducted  in  test  tubes,  each  containing  5  cc.  of  sterilized  water,  portions  of  which 
had  been  previously  treated  with  the  desired  amounts  of  copper  sulphate.  All  tubes  inoculated  with 
a  3  mm.  loop  of  a  14-hour  culture  of  M.  comma. 

It  is  evident  that  the  amount  of  surface  exposed  in  any  ordinary 
copper  tank  would  far  exceed  the  amount  demanded  for  the  above 
results,  and  it  is  likewise  certain  that  after  standing  from  6  to  8  hours 
at  room  temperature  in  a  clean  copper  vessel  water  becomes  safe  to 
drink  even  though  it  may  have  contained  cholera  and  typhoid  germs. 
It  remains  to  be  seen  whether  or  not  the  application  of  these  facts  to 
conditions  in  the  Tropics,  where  cholera  is  abundant,  will  be  of  any 
value.  It  would  seem  that  the .  construction  of  canteens  and  other 
water  vessels  from  copper  might  serve  as  an  additional  safeguard,  if 
not  an  actual  preventive  of  this  disease,  and  would  prove  of  consider- 
able value  where  distillation  or  efficient  filtration  apparatus  is  not  at 
hand. 


40         METHOD    OF    DESTROYING    ALGJ3    IN    WATER    SUPPLIES. 

CONCLUSIONS. 

It  is  believed  that  the  foregoing  experiments  demonstrate  the  possi- 
bility of  the  use  of  copper  sulphate  for  the  destruction  or  prevention 
of  growths  of  algae  in  water  supplies,  and  that  when  used  under  the 
direction  of  a  competent  authority,  it  is  the  only  practicable  remedy 
for  this  trouble  capable  of  universal  application  which  has  ever  been 
proposed.  It  is,  of  course,  probable  that  with  the  experience  which 
must  come  from  a  wider  opportunity  for  testing  this  salt,  many 
improvements  will  be  made  in  the  practical  application  of  the  treat- 
ment to  large  bodies  of  water.  However,  it  is  hoped  that  the  results 
already  obtained,  together  with  trials  now  under  way,  will  make  it 
possible  to  begin  using  this  method  within  a  short  time  upon  a  large 
scale  throughout  the  country. 

NECESSITY    OF   KNOWLEDGE    OF    ORGANISM    AND    CONDITION    IN 

RESERVOIR. 

It  can  not  be  too  strongly  emphasized,  however,  that  harmless  as 
the  method  undoubtedly  is  under  proper  control,  it  must  always  require 
a  certain  amount  of  definite  knowledge  in  regard  to  the  condition  of 
the  reservoir  before  any  treatment  can  be  made,  even  by  those 
thoroughly  able  to  conduct  such  an  experiment.  This  is  regarded  as 
a  fortunate  requisite,  since  it  will  tend  to  prevent  the  irresponsible  or 
careless  dosing  of  reservoirs  by  incompetents,  who  are  occasionally  in 
charge  of  water  supplies. 

Before  the  amount  of  copper  to  be  added  can  possibly  be  known,  it 
is  absolutely  necessary  to  ascertain  the  exact  character  of  the  organ- 
ism causing  the  trouble.  This  will  make  a  microscopical  examination 
of  the  first  importance.  Also,  the  sooner  such  an  examination  reveals 
the  presence  of  the  polluting  form,  the  more  effective  will  be  the  treat- 
ment. If  examinations  are  made  at  short  intervals  during  the  entire 
year,  it  is  possible  to  detect  the  troublesome  forms  at  their  first  appear- 
ance and  by  prompt  treatment  to  destroy  the  algae  before  the  consumer 
is  aware  of  any  difficulty.  The  early  detection  of  the  algse  will  also 
make  a  considerable  difference  in  the  expense  of  the  treatment,  as  it 
may  require  fifteen  or  twenty  times  as  much  copper  to  clean  a  reser- 
voir after  the  bad  odor  and  taste  are  evident  than  it  would  could  the 
application  have  been  made  before  the  organism  began  to  rapidly 
multiply.  In  all  cases  the  use  of  copper  as  a  preventive  rather  than 
a  cure  is  advocated,  and  this  can  not  be  intelligently  applied  unless 
the  microscopical  examinations  are  thorough  and  frequent  at  the  time 
of  year  the  trouble  is  to  be  anticipated. 

On  account  of  the  necessity  of  determining  the  nature  of  the  organ- 
ism and  the  time  of  its  appearance  as  nearly  as  possible,  it  will  become 
as  imperative  for  water  companies  to  employ  some  one  competent  to 


CONCLUSIONS.  41 

make  these  examinations  as  it  now  is  to  have  a  chemist  or  bacteriolo- 
gist. In  fact,  in  regions  where  the  difficulty  from  algae  is  great,  the 
microscopical  examination  must  take  precedence  of  everything  else  as 
a  means  of  keeping  the  water  palatable  and  satisfactory  to  the  consumer. 
In  addition  to  the  character  of  the  organisms  and  the  earliest  possi- 
ble determination  of  their  appearance,  it  has  already  been  pointed  out 
that  the  chemical  constitution,  the  temperature,  and  other  special  con- 
ditions of  the  water  are  factors  in  determining  the  line  of  treatment. 
No  specific  instructions  are  given  in  this  bulletin  for  the  amount  of 
copper  sulphate  which  is  to  be  used  for  each  species  of  algae  which  is 
known  to  affect  water  supplies,  because  it  is  impossible  to  make  a  defi- 
nite statement  without  a  knowledge  of  the  conditions  already  men 
tioned.  Each  reservoir  must  be  regarded  as  an  individual  case,  re- 
quiring special  knowledge  and  a  particular  prescription.  It  is  believed 
that  the  public  water  supplies  of  this  country  are  worthy  of  such  spe- 
cial care,  and  it  would  be  a  matter  of  regret  if  the  method  proposed 
here  should  ever  be  regarded  as  a  universal  panacea  to  be  used  by 
everyone,  regardless  of  the  organism  to  be  eradicated  and  the  condi- 
tion of  the  water. 

APPLICATION  OF  METHOD  FOR  DESTRUCTION  OF  PATHOGENIC  BACTERIA 
NOT  DESIGNED  TO  REPLACE  EFFICIENT  MEANS  OF  FILTRATION 
ALREADY  IN  USE. 

The  use  of  copper  sulphate  in  clearing  polluted  reservoirs  of  patho- 
genic bacteria,  such  as  typhoid  and  cholera,  is  regarded  as  incidental 
to  the  main  purpose  of  the  investigation.  There  already  exists  a  most 
efficient  mean's  of  preventing  the  appearance  of  these  organisms  in 
water  supplies,  and  under  no  circumstances  can  it  be  considered  that 
the  method  as  described  is  expected  to  replace  or  supersede  slow  sand 
or  any  other  efficient  filtration.  There  are  conditions,  however,  which 
sometimes  make  it  desirable  to  thoroughly  sterilize  a  reservoir,  and 
under  those  circumstances  the  use  of .  copper  sulphate  is  believed  to 
offer  a  new  and  adequate  way  of  dealing  with  the  difficulty.  Expe- 
rience has  demonstrated  the  impossibility  of  compelling  consumers  of 
what  may  be  an  infected  water  to  boil  it,  or  observe  other  precautionary 
measures,  and  the  absence  of  proper  filtration  plants  in  a  very  great 
number  of  cities  and  towns  in  this  country  makes  it  necessary  that 
some  efficient  method  for  destroying  disease  germs  in  water  be  employed 
until  the  danger  from  pollution  be  past.  Up  to  this  time  no  satisfac- 
tory and  yet  harmless  method  has  been  known  that  would  become 
effective  in  the  course  of  a  very  few  hours  and  the  cost  of  which  was 
in  the  reach  of  every  community.  It  is  believed  that  the  results  of 
the  experiments  upon  typhoid  and  cholera  germs  described  in  this 
bulletin  indicate  that  it  will  be  possible  under  competent  direction  to 
employ  copper  sulphate  with  perfect  safety  in  any  municipal  water 


42         METHOD    OF    DESTROYING    ALG^E   IN    WATER    SUPPLIES. 

reservoir  which  may  have  become  infected  with  some  nonspore- 
forming  disease  germ.  Its  application  to  barnyard  tanks  and  pools 
as  a  preventive  of  hog  cholera  may  also  prove  to  be  of  value.  Since 
the  selective  toxicity  of  this  salt  renders  it  fatal  to  pathogenic  forms 
peculiar  to  water,  while  the  common  saprophytic  or  beneficial  bac- 
teria are  unaffected,  the  method  is  particularly -well  adapted  for  this 
purpose. 

MEDICINAL    USE. 

While  it  is  not  within  the  province  of  this  bulletin  to  discuss  or 
recommend  any  line  of  medical  treatment,  reference  should  be  made 
to  the  fact  that  certain  eminent  practitioners,  after  reviewing  the 
results  here  published,  are  of  the  opinion  that  the  use  of  copper  in 
cases  of  typhoid  fever  and  related  diseases  should  be  more  thoroughly 
investigated  than  it  has  been  heretofore.  It  was  the  testimony  of  sev- 
eral that  other  intestinal  troubles,  more  recently  presumed  to  be  due 
to  the  presence  of  .certain  disease  germs  in  drinking  water  and  milk, 
had  responded  most  favorably  to  copper  in  one  form  or  another. 

CONDITIONS    UNDER    WHICH    THE    DEPARTMENT    OF    AGRICULTURE    CAN 
FURNISH  INFORMATION  AND  ASSISTANCE  IN  APPLYING  THIS  METHOD. 

The  problem  of  destroying  or  preventing  the  growth  of  algse  by  the 
method  devised  in  the  laboratory  of  plant  physiology  in  water  reser- 
voirs, lakes,  ponds,  water-cress  beds,  and  wherever  these  plants  have 
become  a  pest,  is  one  which  distinctly  comes  within  the  province  of 
the  Department  of  Agriculture.  Definite  instructions  as  to  the  treat- 
ment to  be  followed  will  at  all  times  be  furnished  to  the  proper  author- 
ities who  may  desire  assistance,  and  in  so  far  as  the  limited  facilities 
of  the  laboratory  permit,  determination  will  be  made  of  the  organisms 
causing  the  trouble.  It  is  earnestly  hoped  that  no  tests  of  the  method 
described  here  will  be  made  without  first  consulting  with  the  Depart- 
ment. Those  most  intimately  connected  with  this  work  are  constantly 
gaining  information  and  experience,  and  this  may  prove  of  consider- 
able value,  besides  a  saving  of  expense,  to  those  who  have  occasion  to 
exterminate  algal  pests. 

The  treatment  of  water  supplies  for  the  destruction  of  pathogenic 
bacteria,  or  any  application  of  the  copper-sulphate  method  which  has 
to  do  with  public  health,  is  not  contemplated  or  indeed  possible  by  this 
Department.  The  requests  of  private  individuals  or  unauthorized 
bodies  for  information  or  assistance  can  not  be  granted.  When  State 
or  local  boards  of  health  consider  that  the  disinfection  of  a  water  sup- 
ply is  desirable  and  wish  information  upon  the  subject  it  will  be 
supplied  as'f ully  and  freely  as  possible.  All  experiments  of  this  kind, 
however,  must  be  conducted  by  the  board  of  health,  and  the  Depart- 
ment can  serve  only  in  the  capacity  of  an  adviser. 


SUMMARY.  43 

COST. 

No  definite  estimate  of  the  cost  of  the  treatment  of  a  reservoir  can 
be  given,  because  of  the  special  conditions  governing  each  case.  It  is 
evident,  however,  that  the  maximum  cost  of  material  for  exterminating 
algae  can  not  exceed  50  to  60  cents  per  million  gallons,  and  will  often 
be  less  than  half  this  amount.  The  cost  for  the  copper-sulphate 
destruction  of  bacteria  will  be  from  $5  to  $6  per  million  gallons,  and 
where  lime  or  some  soluble  hydrate  is  used  in  addition  the  cost  would 
be  increased  about  one-third.  The  cost  of  labor  necessary  to  intro- 
duce these  substances  will  be  slight,  since  two  men  can  usually  treat 
from  10,000,000  to  20,000,000  gallons  in  less  than  three  hours. 

SUMMARY. 

The  importance  of  maintaining  all  public  water  supplies  at  the 
highest  degree  of  purity  and  wholesomeness  is  too  well  recognized  to 
require  any  discussion. 

The  disagreeable  odors  and  tastes  so  often  present  in  drinking  water 
are  due  almost  exclusively  to  algae,  although  the  economic  importance 
of  studying  these  plants  has  not  been  recognized  until  recent  years. 

These  algal  forms  are  widely  distributed,  and  reservoirs  in  many 
States  have  been  rendered  unfit  for  use  by  their  presence. 

The  methods  now  known  for  preventing  or  removing  the  odors  and 
tastes  caused  by  algae  have  proved  unsatisfactory,  either  because  of 
prohibitive  expense  or  failure  to  accomplish  result. 

It  is  therefore  desirable  that  some  new,  cheap,  harmless,  and  effective 
method  be  devised  for  ridding  reservoirs  of  these  pests. 

It  has  been  found  that  copper  sulphate  in  a  dilution  so  great  as  to 
be  colorless,  tasteless,  and  harmless  to  man,  is  sufficiently  toxic  to  the 
algae  to  destroy  or  prevent  their  appearance. 

The  mode  of  application  makes  this  method  applicable  to  reservoirs 
of  all  kinds,  pleasure  ponds  and  lakes,  fish  ponds,  oyster  beds,  water- 
cress beds,  etc.  It  is  also  probable  that  the  method  can  be  used  for 
the  destruction  of  mosquito  larvae. 

At  ordinary  temperatures  1  part  of  copper  sulphate  to  100,000  parts 
of  water  destroys  typhoid  and  cholera  germs  in  from  three  to  four 
hours.  The  ease  with  which  the  sulphate  can  then  be  eliminated  from 
the  water  seems  to  offer  a  practical  method  of  sterilizing  large  bodies 
of  water,  when  this  becomes  necessary. 

The  use  of  copper  sulphate  for  the  prevention  of  disease  is  regarded 
as  incidental  and  is  not  designed  in  any  way  to  supplant  efficient  pre- 
ventive measures  now  in  use.  It  is  believed,  however,  that  up  to  this 
time  no  such  satisfactory  means  of  thoroughly,  rapidly,  and  cheaply 
sterilizing  a  reservoir  has  been  known.  Since  the  selective  toxicity  of 


44         METHOD    OF    DESTROYING    ALG,E    IN    WATER    SUPPLIES. 

copper  sulphate  renders  it  fatal  to  pathogenic  forms  peculiar  to  water, 
while  the  saprophytic  or  beneficial  bacteria  are  unaffected,  the  method 
is  particularly  well  adapted  for  this  purpose. 

Definite  knowledge  in  regard  to  what  organisms  are  -present,  the 
constitution  of  the  water,  its  temperature,  and  other  important  facts 
are  necessary  before  it  is  possible  to  determine  the  proper  amount  of 
copper  sulphate  to  be  added.  A  microscopical  examination  thus 
becomes  as  important  as  a  bacteriological  or  chemical  analysis. 

No  rule  for  determining  the  amount  of  copper  sulphate  to  be  added 
can  be  given.  Each  body  of  water  must  be  treated  in  the  light  of  its 
special  conditions. 

The  cost  of  material  for  exterminating  algae  will  not  exceed  50  to  60 
cents  per  million  gallons  and  will  usually  be  less.  The  destruction  of 
pathogenic  bacteria  requires  an  expenditure  of  from  $5  to  $8  per 
million  gallons,  not  including  the  cost  of  labor. 


O 


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